Warning! SPOILERS for Succession season 4 ahead.Succession's season 3 finale sets up its endgame when Tom betrays Shiv during one of her most vulnerable moments, and their marriage continues to crumble in season 4 — but how did Tom betray Shiv? That finale managed the ostensibly impossible task of topping its previous season finale, which prepared the show for a Roy family civil war. In season 3, Kendall (Jeremy Strong) goes against Logan (Brian Cox) with all his artillery, but it soon becomes apparent that he is no match for his father. The other three Roy children struggle to stay in their father's good graces.
However, in the season 3 finale, Logan proves he would never leave Waystar to any of his children, so all their efforts were for nothing. That all changed yet again in Succession season 4 when Logan suddenly passed away while taking a jet to discuss the Waystar/GoJo deal with Lukas Matsson (Alexander Skarsgård). Kendall and Roman (Kieran Culkin) end up sharing the CEO position, leaving Shiv (Sarah Snook) out of the loop. However, Shiv has her own plans that involve cozying up to Matsson, but Tom (Matthew Macfadyen) has the potential to ruin it all.
What Happened To Tom And Shiv In Succession Season 3
Tom betrays Shiv by giving crucial intel to Logan during the Succession season 3 finale. Shiv fights hard for the CEO position and sticks with Logan, even when Kendall, confident he's got what it takes to bring Logan down, invites her to join his side. As it becomes clear that Kendall is losing the battle, Logan becomes interested in acquiring GoJo, a huge tech company run by Lukas Matsson. Matsson offers to buy Waystar instead, and it is Shiv who realizes that she and her siblings are about to be screwed out of their stake in Waystar, rallying Kendall and Roman to stop Logan's plan by not granting him supermajority.
However, Logan is one step ahead and convenes with his ex-wife Caroline (Harriet Walter) to restructure their divorce settlement, giving him a supermajority and destroying Shiv's plan. In a painful scene, Shiv realizes that her mistake wasn't going to see Logan but telling Tom about it, and that's how Tom betrays Shiv. Tom's motivation in tipping Logan in the Succession season 3 ending lies in being mistreated by Shiv since the beginning of their marriage. On their wedding night, Shiv proposes an open marriage (after cheating on Tom repeatedly). Throughout season 3, Tom is worried about going to jail over the cruises scandal and looks at Shiv for reassurance.
However, Shiv is dismissive of his anxiety and only interacts with Tom when she needs him as a pawn in her scheme. Tom's actor Matthew Macfayden shared (via Deadline) that the answer to "how did Tom betray Shiv?" made sense to him: "It’s a pivot by a thousand cuts. From the very beginning, he’s had to take a lot." Tom lost his trust in Shiv, with his world finally crumbling when Shiv tells him, "I may not love you, but I do love you." Therefore, Tom begins to plan his revenge on Shiv, and what better way to do that than to join Logan?
How Tom Betraying Shiv Came To A Head In Season 4
Succession season 4 saw two major fights between Tom and Shiv, proof that the answer to "how did Tom betray Shiv?" was one of the many catalysts. In Succession season 4, episode 7, "Tailgate Party," the couple have a fight for the ages as they air out various misdeeds committed against one another on a balcony. After discovering that Shiv was once again throwing him under the bus, telling everyone he was going to be fired, the argument reached its boiling point, and he brings up the season 2 moment when he literally had to threaten their marriage to get Shiv to ask Logan to sacrifice Kendall instead of him.
Only one episode later, "America Decides," Shiv surprisingly apologizes for what she said the night prior. However, it looks as though the disrespect and consistent grabs for power by both have finally caught up with them, as when she looks for comfort he returns with childish and callous retorts. When Shiv admits that she's pregnant, and the baby is his, he shoots back with, "is that even true?" showing that their marriage really is completely devoid of trust at this point. At one point he even pins Logan's death on her but is quick to add a “sort of” at the end.
One thing that Succession season 4 has made clear, other than the answer to "how did Tom betray Shiv?" is that their marriage is unsalvageable. While audiences may be quick to blame Shiv solely for this, Tom isn't without his own wrongs in the relationship. At certain points, Tom did put Shiv first and he does genuinely love her in his own way. However, these two climactic fights prove that any sort of reconciliation between the two is unlikely to happen, even with a baby on the way. Tom's final move in Succession could be ratting out her plans with Matsson to Logan and Kendall.