Killian

Gregor

Brogan

Julie

Emily Warren

Duncan

Donovan

Collins

Michael Warren

The mission briefing scene was filmed on two days, months apart from each other, with the four actors sitting at the table on one day and Matt McGorry filmed months later.

Shot in 5 days over the course of 15 months.

Originally titled 'Cillian,' which means 'warfare' in Celtic, the name was changed late into production because cast and crew kept pronouncing it incorrectly.