Shel's father explains to him that when he went back in time, the device got damaged when he was teleported on to a sheet of thin ice rather than dry land.

He also explains that he can not leave because Shel and Dave have seen his grave site, and taking him out of that time line would cause a dangerous paradox.

Feeling that his fate is sealed in the event of what happened that night, Shel runs away to live his life out in the timeline.

Together they are able to fake the death of Shel by stealing a body from the scene of an auto accident and placing it in the apartment on the night of the fire.

After eliminating the possibility of a deadly paradox, Dave and Helen set off to find where Shel ran off to.