I may have corrected the bug

controllers/prototype/index.js

@@ -169,3 +169,7 @@ module.exports.userstudy = function(req, res) {
     });
 
 };
+
+module.exports.next = function(req, res) {
+    res.redirect('/prototype/game')
+};

controllers/prototype/urls.js

@@ -9,5 +9,6 @@ module.exports = {
     '/prototype/coin-creator/:scene': 'clicker',
     '/prototype/coin-viewer/:scene': 'viewer',
     '/prototype/coin-checker/:scene': 'checker',
-    '/user-study': 'userstudy'
+    '/user-study': 'userstudy',
+    '/prototype/next': 'next'
 };

controllers/thankyou/index.js

@@ -1,4 +1,8 @@
 module.exports.index = function(req, res) {
+
+    req.session = null;
+    res.locals.session = null;
+
     res.setHeader('Content-Type', 'text/html');
 
     res.render('index.jade', res.locals, function(err, result) {