James Callis & Nick Mohammed on Getting the Call Up for 'Slow Horses' Season 5

To say that Slow Horses has an uneasy relationship with authority is an understatement worthy of an eyeroll and withering insult from Slough House commander-in-chief Jackson Lamb (Gary Oldman).

Outside of the well-meaning but often hapless spies, Season 5 is brimming with pompous, ambitious men in suits – including returning MI5 chief Claude Whelan (James Callis), who is far more House of Lords than “M” from James Bond. However, rising terror attacks in London also affect Mayor Zafar Jaffrey (Nick Mohammed), a slick but insincere politician at risk of being ousted from office by a rival election candidate, the Nigel Farage-coded right-wing populist Dennis Gimbal (Christopher Villiers). As the spies risk life and limb, Claude and Zafar have to wield power without personal problems eating them alive; Telly Visions hopped on a couple of Zoom calls to check in with Callis and Mohammad about their Slow Horses journey.

Callis had a memorable debut in Season 4 and relished returning for one of the most confident and efficient dramas currently airing. “You have a familiarity,” he says. “I was welcomed and supported from when I arrived, but then it’s like you’ve got the badge of season four when you arrive on season five. I haven’t lived in London for a while, and doing season four was my first time back in the UK for some while, and then season five, it feels like you’re cooking with gas.”