Anyway, he appears in all six eps of Series 1 and the first two eps of Series 2 and then was released from his contract. Phew! His role as Lt. Dotsy Doheny is a thankless one, to say the least, and he is a supporting player, though I'm surprised the BBC America site isn't playing up his participation at all. And here's the schedule for the first three episodes.
I'll post another reminder on the day of the premiere. I'm actually curious to see Series 2. I wasn't able to acquire those episodes and only found a vague description as to how his character is written off the show.