Jack was at the Autobot base when Raf called him to report being grounded. He has proven to be athletic as shown when he evaded Airachnid while he was being hunted down and being able to climb on an immobilized Megatron and Knock Out. Bulkhead managed to prevent Fowler from taking the three kids into custody, but a short time later they detected a distress call from Fowler's helicopter, suggesting the agent had been captured by the Decepticons. They stuck around as Optimus returned and it turned out he was being impersonated by a MECH creation. Jack and his fellow humans played a fundamental role in the defeat of Megatron and the restoration of Cybertron.
Neither did the Autobot's hunt for Optimus, however Jack believed that they would be able to commandeer the Decepticon space bridge when it was completed and reach Cybertron.
Their arguing upset Raf, and the pair tried to console him, before Jack noticed a computer display appeared to be showing important data. After discovering that the pair had been kidnapped, he contacted Arcee, who was on mission with Wheeljack and requested their assistance. With a little assistance from Arcee, they stopped the train by running it into Knock Out, and subsequently got Fowler to draft Vogel to ensure his silence. Jack stayed at the base and listened as they reported back that the Decepticons had used a polarity gauntlet to stick them together.