Now it's April of 1945, and Truman has gone from a nobody Missouri senator to the Vice Presidency—but it's clear that FDR doesn't really need his help running things…
Until Truman gets summoned to the White House, where Eleanor tells him that the president has died.
He quickly gets sworn in, and then he summons FDR's cabinet members to tell them he's in charge, now, dudes.
Henry Stimson, the Secretary of War, finally tells Truman about the atomic bomb they've been developing.
Meanwhile in Europe, Hitler's armies are rapidly disintegrating.
The Alsos mission guys storm into Haigerloch trying to find Heisenberg's secret lab.
When they finally find it, they discover that the Germans have been trying (and failing) to build a uranium pile, just like the one Fermi did in his experiment over two years ago. Ha.
According to Kurt Diebner, the leader of Hitler's bomb project, the reason they're so far behind the Americans is because of the elimination of heavy-water production in Norway. Boom, baby.
American soldiers find Germany's entire supply of uranium buried at a nearby farm and ship it off to the United States.
Now that Leslie Groves is positive the Germans aren't anywhere close to getting a nuclear bomb, his attention turns toward preventing the Soviets from getting one. (He's like a kid with a new toy—sharing is hard, yo.)
Alsos teams are going around rounding up top German scientists, and they all seem a little relieved.
When Boris Pash, a member of the Alsos mission, finally finds Heisenberg he's sitting on the porch, waiting for them.
The Soviets are trying to do the same thing—round up German scientists and papers—but they are two steps behind the Americans.