Extreme Measures (Star Trek: Deep Space Nine)

"Extreme Measures" is the 173rd episode of the television series Star Trek: Deep Space Nine. The episode had over 4.3 million viewers when it first aired on television in May 1999, with a Nielsen rating of 4.3 points.^[1]

Set in the 24th century, the series follows the adventures of the crew of the Starfleet-managed space station Deep Space Nine near the planet Bajor, as the Bajorans recover from a decades-long occupation by the imperialistic Cardassians. The later seasons of the series follow a war between the United Federation of Planets and an expansionist empire known as the Dominion, ruled by the shapeshifting Changelings, which has already absorbed Cardassia.

This is the seventh episode of the concluding nine-episode story arc of the series, which brings the Dominion War and other story elements to a close. In episodes preceding this one, the Changelings have fallen victim to a mysterious disease, including Deep Space Nine's security chief Odo, a rogue Changeling who opposes the Dominion. The station physician Julian Bashir has inferred that the Federation's shadowy black ops agency, Section 31, infected Odo deliberately to transmit the disease to the Dominion's Founders. In this episode, Bashir and Chief Miles O'Brien invade the mind of a dying Section 31 agent to find a cure for the disease.

This episode was written by Bradley Thompson and David Weddle and it was directed by Steve Posey. William Sadler returns to play Sloan for third and final time.^[2]