Zap2it has some scoop on a new character coming to Arrow:
A major recurring player will be introduced in episode 13. Halloway is a physically imposing CIA black ops agent who Oliver met on the island. Sent to Lian Yu on a mission that went awry, Halloway has one priority — getting off the island. Unfortunately, he trusts no one, so despite the fact that his interests align with Oliver’s, he may serve as an antagonist — and as a brilliant strategist and expert fighter, he’s definitely dangerous.