Sam Beckett

Dr Samuel Beckett is a time traveling scientist & main protagonist of Quantum Leap.

Sam Beckett had a brother who died in Vietnam, until Sam prevented his brother's death.

In one of his leaps, Sam leaped into the body of Al Mcwhiggin & stop Grimmel, Toht & Kent from killing Harry Solomon. Sam doesn't believe that Harry is an alien.

Sam's friend is Al Calivichi, whom is a hologram that Sam can see & hear.

Sam Beckett is played by Scott Bakula, who also played Captain Archer in Star Trek Enterprise.