The Space and Syfy co-venture Killjoys, from Temple Street Productions, has filled out its top cast.

British actor Hannah John-Kamen has landed the lead role of Dutch, a gorgeous, complicated and deadly killjoy at the top of her game.

And Canadian actors Aaron Ashmore and Luke Macfarlane have also been tapped to play killjoys, or interplanetary bounty hunters.

Production on 10 one-hour episodes of Killjoys is set to start in Toronto on August, ahead of a 2015 debut for the sci-fi series on Space.

Having had success with Orphan Black, also from Temple Street, Space ordered the original scripted sci-fi series  from showrunner Michelle Lovretta, who created Lost Girl.

Syfy later boarded the adventure series as it portrays a trio of interplanetary bounty hunters navigating through political turmoil, questionable morality and complicated relationships.

Killjoys is set on the planet Qresh and a planetary unit Quad, where a highly regulated group of bounty hunters is licensed to pursue a vast range of warrants throughout the galaxy.

Killjoys must follow strict rules, and there are harsh consequences for veering from their mantra that warrants represent everything.

Lovretta will also executive produce Killjoys, along with David Fortier and Ivan Schneeberg of Temple Street Productions.

Chris Grismer will direct the series, with Karen Troubetzkoy producing.

Killjoys writers include Jeremy Boxen, Emily Andras and Adam Barken.

Universal Cable Productions distributes the series worldwide.

– Luke Macfarlane image courtesy of Shutterstock