Saul, of course, is slow on the uptake, as he's been most of the season. But he finally sees what's going on, and in enough time to make what will happen next week really up from grabs.
There are crucial possibilities on all sides of the equation. The terrorist with a conscience, along with Carrie at the train station, may well save the day. (My wife wondered, though, why the Germans didn't deploy some heavy security at the train station, in view of the perceived threat to the airport. Doesn't security up all antes at every vulnerable place, when they receive a threat to any one place?)
Allison, though, to get back to the possibilities on both sides, is an amazing piece of villainous work. She leaves the hospital before Saul can stop her, and even in her weakened condition is still a serious threat with her quick and ruthless thinking.
The Russians who are now 100% directing Allison are not quite believable in their zeal to see the Berlin airport ravaged by sarin gas. The stated reason is that Putin wants Obama and the West to wake up to the threat of ISIS - that's certainly true - but would the Russians be willing to kill so many lives in Berlin to make this happen? I don't know, I'm no expert in counter-terrorism geopolitics, but that seems a little much.
Homeland, though, has really woken up in the past few episodes. I'm looking forward to the season finale next week!
And see also Homeland on Showtime ... Homeland 1.8: Surprises ... Homeland Concludes First Season: Exceptional
different kind of espionage