Here's what happened in the 3rd episode of Fringe:
"In the alternate universe, Walternate informs Colonel Broyles of his plan to use Olivia to discover how to safely traverse universes while the alternate Astrid reports a statistical anomaly to the Fringe team: two pedestrians being killed by distracted bus drivers in as many days. At the scene of the second accident, the Fringe team finds a ballpoint pen - unusual as nearly all writing has been done on digital devices for years. The pen was used by a man named Milo (Michael Eklund) with an incredible ability to calculate cause and effect to an unimaginable degree, and thus to set off chain reactions (in these cases, using a pen to initiate the chain). The Fringe team discovers that Milo previously suffered from low-functioning autism and was given experimental nootropic drugs which enabled the ability. The conclusion of the test would have involved restoring him to his original state (to evaluate potential side effects), which Milo perceived and then sought to avoid by killing those involved. At the scene of a third accident, Olivia spots Milo and gives chase, but he escapes by jumping off the bridge onto a truck that he has directed there using his ability. They later track him down through his sister, and while fleeing he attempts to have Olivia killed with a chain reaction. His attempt fails because she does not react according to his predictions - as an unknown variable was present in the equation (the fact that she is from the prime universe). During the episode, Olivia has several hallucinations, first seeing Peter at the scene of the accident, then Walter (prime) at the medical laboratory, and finally talks to Peter at the end of the episode who informs her she does not belong in the alternate universe offering her unpredictable actions while pursuing Milo as evidence." -- wikipedia
The guy who played Milo was really scary. heh.