Mid-day in a German S-Bahn commuter train. Two boys, JUSTIN and MICHAEL, peer out the window excitedly, the electric engines drone to a halt. An elevated station, their first view of Berlin.

Their father, NICK SKULSKI, puts his thumb over the white “open door” button, mounted on the post. A vet and former “Checkpoint Charlie” M.P., he opens the past, and his future, with just one click.

Unexpectedly, the boys dart out of the open doors and to the wall of windows. Skulski exits slowly, resists the temptation to call out. He’s the model of composure.

Just then – a blinding flash from outside, a percussion so strong it sends the glass flying like a thousand needles. Bodies fly, the train lifts from the track.

Skulski lies in the ICU, covered in salve and a myriad of tubes. He wonders the obvious, seeing the doctor’s grim face lets him know the answer: the boys didn’t make it.

He digs deep; he could give in, leave in one piece, skip this town as he did twenty years before, when the wall came down.

But it’s too late, Skulsky is in the mix again, full on, and this time it cost him more than his rank, his pride – someone took his own flesh and blood. A vow to himself, a promise never to leave Berlin again on someone else’s terms.

An image in his mind: his thumb, pressing the white button, the switch, to the–

“OPEN DOOR “