Our Spanish assassin Julián has captured a full 15 minute quest from the main story of Assassin's Creed: Syndicate (PS4 version) taken from Sequence 4. So if you don't want to spoil things for yourself - don't click play.
In the following gameplay clip, Jacob Frye sneaks into Lambeth Asylum - a facility where some unorthodox biology lessons are taught. There's some good (and mandatory) stealth, interesting environmental resources, a pretty creative assassination and even an introduction made by Charles Darwin himself. Check it out in full: