Predicting what Congress will do is always hard, but the hostages appear to have some prospect of success in what is probably a last-ditch bid for reparations. The confluence of circumstances, said Senator Johnny Isakson, Republican of Georgia and sponsor of the Senate bill, has “brought back the memories for everybody who lived through that time.”

But the effort is baring some ugly tales of captivity, in interviews and in a series of videos made to amplify the hostages’ case. Of the 52 hostages, 39 are still living, and 5 have made videos. They did so with the help of the son of the lawyer who has represented them since soon after Congress passed a law, in 1996, that seemed intended to help them sue. The widows, wives or children of six other hostages also made videos, aimed at Congress.

One of the hostages, Frederick L. Kupke, who was a young communications officer, said in an interview that when they returned home, they did not want “to dwell on all the bad things.” Now he talks about the beatings, the mock firing squads, and being tied up in a bed, day and night, forced for eight hours at a time to press his nose against the wall.

He said he was surprised to have survived; as the embassy was being seized, he went to a roof in the compound with a collection of guns, and then realized that if he were caught, the Iranians would think he was a sniper. When he was caught, he was bound, pummeled, and pushed back and forth between hostile captors; he thought a crowd would tear him apart.