Jump the Shark - S0.E2

X-Files Episode 9x15, bonus feature on the Lone Gunmen R1 DVD set:

When Morris Fletcher approaches agents Doggett and Reyes with information related to "Super Soldiers", they turn to the Lone Gunmen. The Gunmen, however, are knee-deep in a bio-terrorist's plot to release a deadly toxin into the population but the Gunmen find that they may have to make the ultimate sacrifice for their cause.