Synopsis
It's 1952, and deep in Russia Peggy Carter, Howard Stark and Woodrow McCord have come to investigate an alien device. Along the way they picked up 2 Russian teens Tania Belinskaya and Mikhail Uriokovitch, and found themselves in a Hydra base where scientists including Anton Vanko and a woman named Shareen were being forced to track an alien energy source.
Shareen is an alien and the energy source is another being named Xanth who is looking for her. But he is now a living black hole, and he's trying to come through a portal that Hydra created. Woody McCord is the Man On The Wall charged to protect Earth from alien threats. Unfortunately this means he treats all aliens as enemies and he intends to kill Shareen.
Now read on.
Carter talks McCord down because she's healing the injured Tania. Stark agrees because they need her to help stop Xanth. She and Vanko can shut the portal down. In turn Shareen offers to go through the portal to reunite with the man who used to be her lover, then he won't try to get here to Earth. But all 4 of the other adults veto that, for their different reasons.
Shareen explains that the being she now calls the Ebon Seeker is no longer Xanth. It just keeps repeating memories of what Xanth used to be. That endless cycle is what she fled to Earth to escape. And now Shareen and Vanko have fallen in love.
Howard Stark doesn't want Shareen's alien knowledge to fall into the hands of the Russians (or Hydra). This triggers an ideological debate between Stark and Vanko. But eventually they get back to solving their current problem.
It turns out that Shareen's spaceship (that the others crashed into the Hydra base last issue) is made out of her own energy. This might be enough to fool/satisfy Xanth. Shareen figures they only need to give him its power source (the alien artefact the Americans came looking for). Howard goes into the crashed ship to get it.
Tania is unhappy because she came here hoping to find her father among the scientist prisoners, but no such luck. Mikhail did find someone who was probably his mother, but now she seems to have disappeared and he is captured by Russian forces who have invaded the Hydra base.
The others are under attack by the Russians when Howard gets back with the power source. Anton and Shareen feed it to Xanth and the portal closes. Peggy gets shot in the shoulder, and Stark peruades McCord to surrender to the overwhelming Russian troops.
We know that the Russians were financing the Hydra base, but now the leader of the invaders named Igor says that they're pulling the plug. They've come to take Tania along with Vanko and Shareen and the other scientists. Carter, McCord and Stark will be sent back to America.
In an epilog Tania Belinskaya is in jail, Mikhail Uriokovitch is being experimented on about his ability to turn into a bear, Woody McCord is out in space, Anton Vanko and Shareen are working in some Soviet science lab, and Peggy Carter returns home to her repaired house (with added technology courtesy of Howard Stark as promised in #1). Stark himself takes receipt of a copy(?) of the alien power source (smuggled out of Russia) at his Stark Industries Nuclear factory (which at last explains the acronym S.I.N. in this book's title).