President Tom Kirkman (Kiefer Sutherland) will discover that one of his staff was a traitor in the next episode of "Designated Survivor."

Based on the trailer for the episode dubbed as "Lazarus," an anonymous call tells Abe Leonard (Rob Morrow) that the White House has been hiding the truth behind the Capitol bombing. The veteran reporter seems to have divulged the information to the public, making the White House Press Secretary Seth Wright (Kal Penn) and the president's Chief of Staff Emily Rhodes (Italia Ricci) panic.

The trailer also reveals that Hannah Wells (Maggie Q) has already returned to Washington, but her life will be in danger as she investigates the suspects for the Capitol attack and possibly the one who has been double crossing the president the whole time. By the end of the promo video, though, President Kirkman appears to have discovered the identity of the person who has been betraying him and the White House.

Meanwhile, the synopsis for the upcoming episode reveals that both FBI agent Wells and the former FBI Deputy Director Jason Atwood (Malik Yoba) will report their findings from their investigation in North Dakota to the president, and it seems like they managed to uncover a major lead during their trip.

On the other hand, the president will have to start considering the names of the candidates for vice-presidency. This will make the new Speaker of the House Kimble Hookstraten (Virginia Madsen) in the middle of a major scandal.

In the previous episode, Hookstraten clarified that she was expecting to be offered the vice-presidential position after she successfully managed to help pass the gun control bill in the House of Representatives. However, the upcoming scandal could affect the president's decision in choosing the new vice-presidential candidate.

ABC will air the next episode of "Designated Survivor" on Wednesday, April 26, at 10 p.m. EDT.