Time phone

The time phone is a way of communicating between different time periods, devised by Perceptor aboard the Lost Light.

Fiction

2005 IDW continuity

When Brainstorm created a time machine to change history by preventing Megatron from ever coming to lead the Decepticons in the first place, Rodimus, Megatron and Perceptor gathered a team to follow him back in time to stop him. They arrived in Alyon, four million years in the past, where Orion Pax and his gang of rebels were defending a hot spot from the Senate's forces and while Rodimus was distracted by the sudden appearance of Trailbreaker, Pax found the ringing time phone. On the other end was present-day Megatron, and the two had a conversation regarding Megatron's conflicting loyalties. After they saved the sparks from the hot spot, All Our Parlous Yesterdays the group of time travellers pursued Brainstorm further back, to Maccadam's New Oil House and then, after consulting with Perceptor and Ultra Magnus via the time phone, to the same place but earlier in 4th Cycle 499, where Rung accidentally started a fight over a curly straw that got Megatron wrongly arrested. In the present day, Megatron worked out Brainstorm's plan Stet and so the team were sent back to five million years ago in Con Facility 113, the time and place of Megatron's construction. After disarming Brainstorm and talking him down, Perceptor told Rodimus that their mission wasn't over and that time was still being rewritten, because to everyone's surprise Rewind stepped up and killed the nascent Megatron instead.

Rewind justified his actions by revealing that in the new timeline the galaxy at large was spared the brunt of the Transformers' war with present-day Megatron listening over the time phone. However, Whirl refused to accept letting the Functionists win and stole Brainstorm's spare Point One Percenter spark from Luna 1 to revive Megatron. Ultra Magnus called from the present day to let them know that this action had preserved their existing timeline, but that they were stuck in the past because the Lost Light's quantum engines were out of power. Faced with this bleak scenario, Tailgate came up with a plan—to use the time phone to call Cybertron on the day of the Lost Light's launch and convince themselves not to follow the same path. After Rodimus, Rung, Chromedome and Riptide all chipped in with advice to their past selves, Cyclonus sneered at them, pointing out that even if their message got through, they would have undone all the good works they had achieved on their mission and Tailgate would have died of cybercrosis. Predestination: An Expert's Guide The call did reach Cybertron but just too late, after the Lost Light's apparent destruction on launch, and in a fragmented form that omitted the most important information anyway. How to Say Goodbye and Mean It

Fortunately, Perceptor called Rodimus to tell him that they had a plan, teleporting him and Cyclonus to Unitrex where they were able to "invent" quantum engines in the past, charging their time case and inadvertently transporting the Unitrex-1 some way into the future. Having decided that the timeline was now safe, Rodimus told Perceptor to bring them all back to the present. Predestination: An Expert's Guide