Jacob Frye is the playable Frye twin who appears alongside Evie in Assassin's Creed Syndicate.
The game follows twins Jacob and Evie Frye as they travel to London in 1868, during the Industrial Revolution. Both are Assassins, but they approach the conflict differently. Jacob favors direct action and builds a street gang called the Rooks, while Evie is more focused on stealth, investigation, and locating an artifact known as the Piece of Eden.
Players can switch between the twins during much of the campaign, and each has distinct abilities and skill specializations. Their partnership is central to the story, so Jacob is not a replacement for Evie; he is her brother and co-protagonist.
Henry Green, also known as the Assassin Jayadeep Mir, supports the twins in London. Shay Cormac and Liam O'Brien belong to Rogue and Assassin's Creed III respectively, making them unrelated to the Frye family.