The closing moments of Monday’s Season 8 return of Murdoch Mysteries–“On the Waterfront, Part One”–isn’t like anything the series has done before. A showdown at Toronto’s waterfront between union workers–led by the dastardly O’Shea brothers–faces off against Det. William Murdoch (Yannick Bisson) and the rest of the Constabulary. Meanwhile, Dr. Julia Ogden (Hélène Joy) and Dr. Julia Grace (Georgina Reilly) are caught up in their own conflagration between members of the Suffragette movement and men who don’t take kindly to women wanting to vote.

The carefully choreographed scenes that cut back and forth from wharf to city square ramp up in tension to a boiling point viewers aren’t used to seeing from the CBC drama.

“It was fun to shoot,” Jonny Harris says of the scene between the dock workers and the police force, of which his Constable George Crabtree is a part. “All the dock workers were big sort of stunt guys and all the cops are station cops that have been on the show for years … not huge guys. Everybody went for broke on every take that day.” The conflagration at the dock is a result of union guys refusing to back down against the police, but it’s also about a police force seeking justice for the vicious attack on Inspector Thomas Brackenreid (Thomas Craig) at the hands of the O’Sheas. The Season 7 finale “The Death of Dr. Ogden,” saw the engagement of Murdoch and Ogden announced, but that happy moment was tempered by the discovery of Brackenreid’s beaten body on a dusty Toronto street.

Monday’s return does address the fate of the beloved Brackenreid while introducing a new boss in Det. Hamish Slorach (Patrick McKenna, Remedy), a man very unlike his predecessor.

As for Crabtree, Season 8 represents growth for the character. His up-and-down relationship with Dr. Grace is put on the back burner when a new lady enters his life in the form of a lady from the series’ past. Harris says Tamara Hope, who appeared in the very first episode of Murdoch Mysteries in 2008, reprises her role as Edna Garrison, a single mom struggling to make ends meet. Crabtree becomes a surrogate father to Edna’s son, a departure for a character usually relied upon for laughs.

“Over so many years, you want to keep your characters that people fell in love with, but you do need to make significant changes otherwise it just becomes redundant,” Harris explains. Does he ever wish Crabtree would show a dark side to him? The Newfoundland native smiles.

“He’s a pretty good guy,” Harris says. “I was liking Crabtree and Grace last year because they each had their moments of being petulant and jealous. I thought that was kind of nice. You have the romance between Ogden and Murdoch, which has always had its obstacles and troubles, but they’re mostly pure of heart. With Crabtree and Grace, it had to do with envy.”

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