diff --git a/app/controllers/manager/dossiers_controller.rb b/app/controllers/manager/dossiers_controller.rb
index d42d335ce..23068d4c4 100644
--- a/app/controllers/manager/dossiers_controller.rb
+++ b/app/controllers/manager/dossiers_controller.rb
@@ -1,4 +1,12 @@
 module Manager
   class DossiersController < Manager::ApplicationController
+    def change_state_to_instruction
+      dossier = Dossier.find(params[:id])
+      dossier.update(state: 'en_instruction', processed_at: nil, motivation: nil)
+      dossier.attestation&.destroy
+      logger.info("Le dossier #{dossier.id} est repassé en instruction par #{current_administration.email}")
+      flash[:notice] = "Le dossier #{dossier.id} est repassé en instruction"
+      redirect_to manager_dossier_path(dossier)
+    end
   end
 end
diff --git a/app/lib/pipedrive/deal_adapter.rb b/app/lib/pipedrive/deal_adapter.rb
index 68f9725c9..b86654771 100644
--- a/app/lib/pipedrive/deal_adapter.rb
+++ b/app/lib/pipedrive/deal_adapter.rb
@@ -22,8 +22,8 @@ class Pipedrive::DealAdapter
   end
 
   def self.get_deals_ids_for_person(person_id)
-    Pipedrive::API.get_deals_for_person(person_id)
-      .map { |datum| datum['id'] }
+    deals = Pipedrive::API.get_deals_for_person(person_id) || []
+    deals.map { |datum| datum['id'] }
   end
 
   def self.update_deal_owner_and_stage(deal_id, owner_id, stage_id)
diff --git a/app/views/dossiers/_messagerie.html.haml b/app/views/dossiers/_messagerie.html.haml
index ca223136d..4c1c22da6 100644
--- a/app/views/dossiers/_messagerie.html.haml
+++ b/app/views/dossiers/_messagerie.html.haml
@@ -20,7 +20,7 @@
         = render partial: 'dossiers/commentaires/form', locals: { dossier_facade: @facade }
 
     .last-commentaire.clearfix.hidden-print
-      - if last_comment = dossier_facade.commentaires.first
+      - if last_comment = dossier_facade.commentaires.last
         %div
           DERNIER MESSAGE
           = render partial: 'dossiers/commentaires/commentaire', object: last_comment
diff --git a/app/views/manager/application/_navigation.html.erb b/app/views/manager/application/_navigation.html.erb
index 60c28e051..bb217b350 100644
--- a/app/views/manager/application/_navigation.html.erb
+++ b/app/views/manager/application/_navigation.html.erb
@@ -12,7 +12,7 @@ as defined by the routes in the `admin/` namespace
 
   <hr />
 
-  <% Administrate::Namespace.new(namespace).resources.reject { |resource| resource.resource == 'dossiers'}.each do |resource| %>
+  <% Administrate::Namespace.new(namespace).resources.each do |resource| %>
 
     <%= link_to(
       display_resource_name(resource),
diff --git a/app/views/manager/dossiers/show.html.erb b/app/views/manager/dossiers/show.html.erb
new file mode 100644
index 000000000..4213b3e0d
--- /dev/null
+++ b/app/views/manager/dossiers/show.html.erb
@@ -0,0 +1,48 @@
+<%#
+# Show
+
+This view is the template for the show page.
+It renders the attributes of a resource,
+as well as a link to its edit page.
+
+## Local variables:
+
+- `page`:
+  An instance of [Administrate::Page::Show][1].
+  Contains methods for accessing the resource to be displayed on the page,
+  as well as helpers for describing how each attribute of the resource
+  should be displayed.
+
+[1]: http://www.rubydoc.info/gems/administrate/Administrate/Page/Show
+%>
+
+<% content_for(:title) { t("administrate.actions.show_resource", name: page.page_title) } %>
+<% dossier = page.resource %>
+
+<header class="main-content__header" role="banner">
+  <h1 class="main-content__page-title">
+    <%= content_for(:title) %>
+  </h1>
+
+  <div>
+    <% if dossier.termine? %>
+      <%= link_to 'repasser en instruction', change_state_to_instruction_manager_dossier_path(dossier), method: :post, class: 'button' %>
+    <% end %>
+  <div>
+</header>
+
+<section class="main-content__body">
+  <dl>
+    <% page.attributes.each do |attribute| %>
+      <dt class="attribute-label" id="<%= attribute.name %>">
+      <%= t(
+        "helpers.label.#{resource_name}.#{attribute.name}",
+        default: attribute.name.titleize,
+      ) %>
+      </dt>
+
+      <dd class="attribute-data attribute-data--<%=attribute.html_class%>"
+          ><%= render_field attribute %></dd>
+    <% end %>
+  </dl>
+</section>
diff --git a/config/routes.rb b/config/routes.rb
index bfaf02af0..b6617d7c8 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -6,6 +6,10 @@ Rails.application.routes.draw do
       post 'whitelist', on: :member
     end
 
+    resources :dossiers, only: [:index, :show] do
+      post 'change_state_to_instruction', on: :member
+    end
+
     resources :administrateurs, only: [:index, :show, :new, :create] do
       post 'reinvite', on: :member
       put 'enable_feature', on: :member
diff --git a/spec/lib/pipedrive/deal_adapter_spec.rb b/spec/lib/pipedrive/deal_adapter_spec.rb
new file mode 100644
index 000000000..bce1ad0e5
--- /dev/null
+++ b/spec/lib/pipedrive/deal_adapter_spec.rb
@@ -0,0 +1,27 @@
+require 'spec_helper'
+
+describe Pipedrive::DealAdapter do
+  let(:url) { PIPEDRIVE_API_URL }
+  let(:status) { 200 }
+  let(:body) { '{}' }
+
+  before do
+    stub_request(:get, url)
+      .to_return(status: status, body: body)
+  end
+
+  describe ".get_deals_ids_for_person" do
+    let(:url) { %r{/persons/1/deals\?*} }
+    subject { Pipedrive::DealAdapter.get_deals_ids_for_person('1') }
+
+    context "with valid data" do
+      let(:body) { '{ "success": true, "data": [ { "id": 34 }, { "id": 35 } ] }' }
+      it { is_expected.to eq [34, 35] }
+    end
+
+    context "when no data are returned" do
+      let(:body) { '{ "success": true, "data": null }' }
+      it { is_expected.to eq [] }
+    end
+  end
+end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index e04cac0f7..e693207dd 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -72,6 +72,7 @@ DatabaseCleaner.strategy = :transaction
 TPS::Application.load_tasks
 
 SIADETOKEN = :valid_token if !defined? SIADETOKEN
+PIPEDRIVE_TOKEN = :pipedrive_test_token if !defined? PIPEDRIVE_TOKEN
 
 include Warden::Test::Helpers