1x16 - Mysterious Ways

When a cop's partner is shot to death while investigating a break-in, the cop feels responsible. That night, the distraught cop says a silent prayer--if only he could have this day back. The cop wakes the next morning to discover he's gotten his wish--he's living yesterday all over again. But unfortunately, he's the only one who knows it. Through this investigation Declan and Peggy learn a lesson about altering the course of destiny.