I love Ethan Hawk and he is excellent as Agent Lennox. Lennox is in Berlin with Emma Wallace, his CIA partner and fiance. Emma is killed when she discovers that the man she thinks is her husband is actually the criminal she has been tracking. She discovers Lennox has been doubled by Project Helix.
I love this scene, Lennox at the safehouse, mourning Emma's death with a bottle of vodka. The kitchen is dimly lit, the house quiet with sadness. Sydney sympathizes with Lennox, because she herself works along side Vaughn, her new boyfriend and because her fiance was killed. Lennox kisses her, in a grief-stricken, alcoholic stupor and then the two are confronted by security agents.
Lennox is taken in when the CIA learns that he has been doubled. With the possibility that Lennox may actually be the doctor behind Project Helix, the CIA subjects him to tests and an eye exam. In a train track showdown, Sydney is able to weed out the double and kill him- destroying the Helix protocol in the process. Um, that will bite her in the ass later!
PS. I love the scene when they are testing his eyes- there is a call back later when Will has his eyes checked, because the CIA thinks he may be a double. Very cool!