 Peter begs September to send him back to the original timeline but September assures him that this is where he is meant to be before teleporting away.In the 5th season episodes "Anomaly XB-6783746" and "The Boy Must Live", it is revealed that after the events of the fourth season, the Observers removed September's observer technology and conducted "biological reversion" experiments on him, causing him to transform into a human.As a human, he assumed the name Donald O'Connor.