This post contains spoilers from The Diplomat season 3 episode 1 from this point forward.
Following the shocking season 2 finale, The Diplomat season 3 returns with tensions high. Last season, Kate and Hal learned about Vice President Penn's role in the attack on the British warship and planned to use that information to get Kate the vice presidency. However, when Hal dropped the news on President Rayburn, well, the POTUS had a heart attack and dropped dead.
In an instant, Vice President Penn became President Penn, and The Diplomat season 3 picks up right where we left off, with Kate and everyone else running back inside to make sense of what's happening and to secure Penn. Kate instructs Hal not to say anything to anyone else. Penn enters a secure SCIF and discusses the situation with Billie, who's still in DC. When Penn asks who Rayburn was speaking to when he died, and Kate admits he was talking to Hal.
Immediately, Penn takes the defensive against Kate, but there's no time for their trust issues. Next up, the group discusses where to swear Penn in as president. Kate argues for the embassy as the site of her swearing in and wins. She next privately calls Eidra to ask about Hal and demand that she ends his debrief with the FBI and keep him from talking. It's decided that Billie will address the nation with the announcement. With that, Penn and the team are off to the embassy.

Hal pushes Kate as vice president amid political chaos
Once they arrive at the embassy, Penn watches Billie's address on Kate's phone while they work to secure the premises. Penn takes over Kate's office and the two speak alone, and Penn also wants to keep Kate right where she can keep an eye on her. Meanwhile, the team are trying to make the embassy lobby work for a presidential swearing in, which is no simple task.
Hal enters the office and immediately says, "I killed him." Without missing a beat, Kate replies, "No." He admits to telling Rayburn about Penn's role in the attack. The Wylers plead their case that the president needed to know about the attack, and now she does. They have no intention of telling anyone else, and they are no longer her biggest problem. Once again, Kate seems to have convinced Penn.
Stuart and Kate take a call from Trowbridge, who insists on being present at Penn's swearing in ceremony, even though the Americans don't want foreign leaders standing next to Penn. He also agrees to take Margaret Roylin off their hands, which seems to help his case. Kate's furious at Hal for this situation and also about the fact that she now has to be VP to keep a watch on Penn.
Hal plants the seed with Stuart to start the rumor about Kate becoming the vice president, though that's not on anyone's mind but his. Penn agrees to giving Roylin asylum before talking to the president's widow. While everyone talks about how to shut the blinds to give Penn privacy, Hal takes it upon himself to enter the office and just do it. Kate tells Eidra to take Hal to offer Roylin asylum.

Penn reveals who she wants to be vice president
Hal and Eidra's meeting with Roylin isn't conclusive, as Roylin seems to think she isn't safe wherever she goes. Kate and Penn continue their best frenemies routine as Kate helps Penn turn one of her spare tops from the bottom drawer of her desk appear as a fancy blouse under her blazer. Who knew Kate was a fashion MacGuyver? Penn feels guilt for Rayburn's death, but Kate maintains fairness and insists all Penn did was make a tough call.
When everyone gathers for the ceremony, Kate and Dennison embrace a little bit too long, which Hal appears to notice from a distance. Trowbridge brought a Bible for Penn to use and insists on giving it to her right away, agreeing to not be seen in photos. The ceremony goes off without a hitch, even though it was stitched together haphazardly against all odds.
Later, Nora asks if Penn tapped a VP after Stuart was in her ear about Kate. She's unconcerned with VP, and everything else melts away when Penn's husband Todd (Bradley Whitford) finally arrives. Hal pleads to the Penns that Kate should be the vice president. He's always one to use an opportunity when he can get it. (Not to blame him, but that's how Rayburn died.)
Roylin has been moved to a new location and takes a pill with tea. Then she takes another... and another... and another... and lots more. Kate and Hal are called in to speak with Penn. Before dropping the bombshell, Penn admits that what she's about to say will be a "pain point" and apologizes. She then reveals that she wants Hal — not Kate! — to be her vice president. The episode ends as the Wylers process the information in shock. Hal as the vice president?!