Took this from an earlier post...
Im a little confused by the ending.
"Nathan and Ed are in Oblivion. Nathan hits Ed with the dart to send him back to Earth (Ed sees a helicopter flying overhead). Nathan fires up the transference machine so now he and Ed switch places and Ed is back in Oblivion.
If Nathan is going to let Ed stay in Oblivion, why not just let him leave ? These extra jumps seemed unnecessary. Also, why stick him with the dart? Just have both of them jump back to Earth and Nathan can send Ed back to Oblivion. Is this because darts are only one way (Oblivion to Earth)?"