diff --git a/app.js b/app.js
index d4b545b3adbdd0f7c0e83130866a542013810afe..37888bdfff393e34c53a51dd93c09868edf59b83 100644
--- a/app.js
+++ b/app.js
@@ -9,7 +9,6 @@ const flash = require('connect-flash');
 const LocalStrategy = require('passport-local').Strategy;
 
 const authRouter = require('./routes/auth');
-const usersRouter = require('./routes/users');
 const adsRouter = require('./routes/ads');
 
 const app = express();
@@ -22,6 +21,7 @@ require('dotenv').config();
 mongoose.connect(process.env.DB_CONNECTION_STRING, {
   useNewUrlParser: true,
   useUnifiedTopology: true,
+  useFindAndModify: false,
 });
 
 const User = require('./models/user').User;
@@ -95,7 +95,6 @@ app.use(function(req, res, next) {
 });
 
 app.use('/', authRouter);
-app.use('/users', usersRouter);
 app.use('/ads', adsRouter);
 
 // catch 404 and forward to error handler
diff --git a/models/ad.js b/models/ad.js
index 7ba797671c530435d835c397b3daa936110e6d26..cd5374a37096bd50ac9f0b7033db993d6b2839a3 100644
--- a/models/ad.js
+++ b/models/ad.js
@@ -37,7 +37,6 @@ const postTemplate = {
   },
   date: {
     type: Date,
-    get: (d) => d && d.toLocaleDateString(),
   },
 };
 
diff --git a/public/javascript/script.js b/public/javascript/script.js
index b588a882079c3b262ed8a5307a4e78fbe1d59681..9b034bfd7024dae081566b4f76d9ebd8c44a4ae5 100644
--- a/public/javascript/script.js
+++ b/public/javascript/script.js
@@ -1,3 +1,6 @@
+/**
+ * Registers listeners to messages so that they can be closed.
+ */
 function setMessagesListeners() {
   const messages = document.querySelector('.msgs');
   if (messages) {
@@ -11,6 +14,31 @@ function setMessagesListeners() {
   }
 }
 
+/**
+ * Registers listeners to answer buttons so that it displays reply form.
+ */
+function setReplyListeners() {
+  const replyButtons = document.querySelectorAll('.reply-btn');
+
+  replyButtons.forEach((btn) => {
+    const hiddenForm = btn.parentNode && btn.parentNode.querySelector('.reply-form');
+    if (hiddenForm) {
+      btn.addEventListener('click', (e) => {
+        if (btn.dataset.shown === 't') {
+          btn.dataset.shown = 'f';
+          btn.innerText = 'Répondre';
+          hiddenForm.style.display = 'none';
+        } else {
+          btn.dataset.shown = 't';
+          btn.innerText = 'Cacher';
+          hiddenForm.style.display = 'block';
+        }
+      });
+    }
+  });
+}
+
 document.addEventListener('DOMContentLoaded', function() {
   setMessagesListeners();
+  setReplyListeners();
 });
diff --git a/public/stylesheets/style.css b/public/stylesheets/style.css
index 2d6029d0814209d29c5d2c9ace51dd79555f9cd6..910a8befcb44ab516ae713550aaf053beb33dbf0 100644
--- a/public/stylesheets/style.css
+++ b/public/stylesheets/style.css
@@ -82,4 +82,8 @@ span.error-message {
   max-width: 25%;
   height: 100%;
   margin-bottom: 15px;
+}
+
+.reply-form {
+  display: none;
 }
\ No newline at end of file
diff --git a/routes/ads.js b/routes/ads.js
index 28879a956c5e087572f5454e524ec6527bb39d87..aa55cf5ef6606ba6ef1ace0fb6966f44bd21ba4a 100644
--- a/routes/ads.js
+++ b/routes/ads.js
@@ -14,59 +14,57 @@ router
     .get('/create', authorize('agent'), function(req, res) {
       res.render('ads/create');
     })
-    .post(
-        '/create',
-        authorize('agent'),
-        upload.array('pictures', 3),
-        function(req, res, next) {
-          const body = req.body;
-          const id = body.id;
-
-          const formData = {
-            title: body.title,
-            type: body.type,
-            transactionStatus: body.transactionStatus,
-            price: body.price.replace(',', '.'),
-            published: body.published === 'on',
-            description: body.description,
-            availabilityDate:
-          body.availabilityDate === '' ? null : body.availabilityDate,
-          };
+    .post('/create', authorize('agent'), upload.array('pictures', 3), function(
+        req,
+        res,
+    ) {
+      const body = req.body;
+      const id = body.id;
 
-          if (req.files.length) {
-            formData.pictures = req.files.map((f) => ({
-              name: f.fieldName,
-              body: f.buffer,
-            }));
-          }
+      const formData = {
+        title: body.title,
+        type: body.type,
+        transactionStatus: body.transactionStatus,
+        price: body.price.replace(',', '.'),
+        published: body.published === 'on',
+        description: body.description,
+        availabilityDate:
+        body.availabilityDate === '' ? null : body.availabilityDate,
+      };
 
-          if (id) {
-            // Peut-être charger l'objet en amont et le retourner si erreur ?
-            adModel.Ad.updateOne({_id: id}, {$set: formData})
-                .exec()
-                .then(() => {
-                  req.flash('success', 'Mise à jour réussie !');
-                  res.redirect('/ads/');
-                })
-                .catch((reason) => {
-                  res.render('ads/create', reason);
-                });
-          } else {
-            const newAd = new adModel.Ad(formData);
-
-            newAd
-                .save()
-                .then(() => {
-                  req.flash('success', 'Mise à jour réussie !');
-                  res.redirect('/ads/');
-                })
-                .catch((reason) => {
-                  console.error(reason);
-                  res.render('ads/create', reason);
-                });
-          }
-        },
-    )
+      if (req.files.length) {
+        formData.pictures = req.files.map((f) => ({
+          name: f.fieldName,
+          body: f.buffer,
+        }));
+      }
+
+      if (id) {
+      // Peut-être charger l'objet en amont et le retourner si erreur ?
+        adModel.Ad.updateOne({_id: id}, {$set: formData})
+            .exec()
+            .then(() => {
+              req.flash('success', 'Mise à jour réussie !');
+              res.redirect('/ads/');
+            })
+            .catch((reason) => {
+              res.render('ads/create', reason);
+            });
+      } else {
+        const newAd = new adModel.Ad(formData);
+
+        newAd
+            .save()
+            .then(() => {
+              req.flash('success', 'Mise à jour réussie !');
+              res.redirect('/ads/');
+            })
+            .catch((reason) => {
+              console.error(reason);
+              res.render('ads/create', reason);
+            });
+      }
+    })
     .get('/update/:id', authorize('agent'), function(req, res, next) {
       const id = req.params.id;
 
@@ -85,6 +83,71 @@ router
     })
     .get('/delete/:id', authorize('agent'), deleteAdAction)
     .delete('/delete/:id', authorize('agent'), deleteAdAction)
+    .post('/:id/questions/create', authorize('client'), function(req, res) {
+      const question = {
+        author: req.user.name,
+        body: req.body.body,
+        date: new Date(),
+      };
+
+      adModel.Ad.findByIdAndUpdate(
+          req.params.id,
+          {
+            $push: {
+              questions: question,
+            },
+          },
+      )
+          .then((ad) => {
+            res.status(201);
+            req.flash('success', 'Question publiée.');
+            res.redirect('/ads/' + ad.id);
+          })
+          .catch((err) => {
+            console.error(err);
+            req.flash(
+                'error',
+                'Une erreur est survenue lors du chargement des données.',
+            );
+            res.redirect('/ads/' + ad.id);
+          });
+    })
+    .post(
+        '/:id/questions/:questionId/answers/create',
+        authorize('client'),
+        function(req, res) {
+          const answer = {
+            author: req.user.name,
+            body: req.body.body,
+            date: new Date(),
+          };
+
+          adModel.Ad.findByIdAndUpdate(
+              req.params.id,
+              {
+                $push: {
+                  'questions.$[target].answers': answer,
+                },
+              },
+              {
+                arrayFilters: [{'target._id': req.params.questionId}],
+              },
+          )
+              .then((ad) => {
+                res.status(201);
+                req.flash('success', 'Réponse publiée.');
+                res.redirect('/ads/' + ad.id);
+              })
+              .catch((err) => {
+                console.error(err);
+                req.flash(
+                    'error',
+                    'Une erreur est survenue lors du chargement des données.',
+                );
+                res.redirect('/ads/' + ad.id);
+              });
+        },
+    )
     .get('/:id/picture/:index', function(req, res, next) {
       adModel.Ad.findOne({_id: req.params.id})
           .then((ad) => {
diff --git a/routes/users.js b/routes/users.js
deleted file mode 100644
index 7bea77ff87f5ab901ed9e69934986a398c3660b5..0000000000000000000000000000000000000000
--- a/routes/users.js
+++ /dev/null
@@ -1,9 +0,0 @@
-const express = require('express');
-const router = new express.Router();
-
-/* GET users listing. */
-router.get('/', function(req, res, next) {
-  res.send('respond with a resource');
-});
-
-module.exports = router;
diff --git a/views/ads/show.hbs b/views/ads/show.hbs
index aa875079d4a4731abcda8331156ab7c04e8f7c3d..40ff5b160a4fcec00e93645941726d03f19b87e1 100644
--- a/views/ads/show.hbs
+++ b/views/ads/show.hbs
@@ -20,6 +20,69 @@
     <h2>Description</h2>
     <p>{{ad.description}}</p>
   </section>
+  <section>
+    <header>
+      <h2>Questions</h2>
+    </header>
+    {{#authorize "client"}}
+    <section>
+      <h3>Poser une question</h3>
+      <form action="/ads/{{ad._id}}/questions/create" method="POST">
+        <textarea name="body" rows="2" cols="60" placeholder="Écrire ici...">
+        </textarea><br/>
+        <input type="submit" value="Envoyer"/>
+      </form>
+    </section>
+    {{/authorize}}
+    <details class="questions">
+      <summary>
+        <h3 style="display: inline-block;">
+          Voir les questions
+        </h3>
+      </summary>
+      {{#with ad as |ad|}}
+      {{#each ad.questions}}
+      <section class="question">
+        <main>
+          <p>{{body}}</p>
+        </main>
+        <time>Posée le {{dateToLocaleString date}} par {{author}}</time>
+        {{#authorize "agent"}}
+        <section class="reply-control">
+          <button class="reply-btn">Répondre</button>
+          <section class="reply-form" data-shown="f">
+            <form
+                action="/ads/{{ad._id}}/questions/{{_id}}/answers/create"
+                method="POST">
+              <textarea name="body" rows="2" cols="60" placeholder="Écrire ici...">
+              </textarea><br/>
+              <input type="submit" value="Envoyer"/>
+            </form>
+          </section>
+        </section>
+        {{/authorize}}
+        {{#if this.answers.length}}
+        <details class="replies">
+            <summary>Réponses</summary>
+            {{#each this.answers}}
+            <section class="reply">
+              <main>
+                <p>{{body}}</p>
+              </main>
+              <time>Réponse de {{author}} le {{dateToLocaleString date}}</time>
+            </section>
+            {{/each}}
+          </details>
+        </section>
+        {{else}}
+        <p>Aucune réponse</p>
+        {{/if}}
+      {{else}}
+      <p>Aucune question.</p>
+      {{/each}}
+      {{/with}}
+    </details>
+  </section>
   {{#authorize "agent"}}
   <footer>
     <a href="/ads/update/{{ad._id}}">Mettre à jour</a>