Fragile Balance

S7 E3: Meanwhile Selmak looks at O'Neill's test results and says the boy is not O'Neill but a clone. Carter Daniel and Teal'c who have been researching alien-abduction cases similar to O'Neill's surmise that whichever of the Asgard was responsible for the abductions replaced the test subjects with clones until he was finished studying them then switched them back. O'Neill's regression was a mistake of which the Asgard researcher was unaware. SG-1 plans to intercept the next switch in order to apprehend him.