William Shatner’s guest appearance on Murdoch Mysteries has been discussed almost as much as whether or not Crabtree would be freed from prison. Shatner portrays American novelist, essay writer and speaking Mark Twain in Monday’s new instalment, “Marked Twain,” and doesn’t disappoint. Here are some key facts about tonight’s case before it begins.

Margaret is back!

Fans of Arwen Humphreys rejoice, because Margaret is back and better than ever. Thomas is being considered for a membership at the exclusive Empire Club and Margaret is doing her best to make sure he gets in. The Empire Club is a real thing; established in 1903 (the year this season of MM takes place) and was created to keep ties with Britain strong. And while Mark Twain never really spoke there, several other notable folks did, including Winston Churchill, Ronald Reagan, A.Y. Jackson, Roberta Bondar, Indira Gandhi and Prince Philip.

Not everyone loves Mark Twain

He may have written beloved books in The Adventures of Tom Sawyer and Adventures of Huckleberry Finn, but not everyone liked Twain at the time. He was against the way countries like Britain had settled territory around the world through colonization and military force. Hence, Mr. Twain becomes a target.

A certain someone is Twain’s biggest fan

The Curse of the Pharaohs makes an appearance

In a very cool way.

Higgins goes undercover

The Constable First Class dons a top and tails, slicks his hair back, adopts a British accent and ingratiates himself with the Empire Club’s members to suss out the wannabe assassin.

Murdoch Mysteries airs Mondays at 8 p.m. on CBC.