Season 4, Ep 3 the "Dracula" reference
Not to be picky but first the book they use is far too thin to be "Dracula". It is a long, involved, yet still engrossing tale.
Also, Matilda says Dracula arrived in Whitechapel when he really arrived in Whitby. His main abode was Whitby's Carfax Abbey, a decommissioned church, but he did have "safe houses" all around London and may have had one in Whitechapel but it was not where he initially arrived.