Recap: Star Trek Deep Space Nine S 01 E 05 Babel
O'Brien has been having a bad day. He's been run ragged all across DS9, fixing one broken system after another. While fiddling with the main floor replicators, his day gets worse. He's been infected with an aphasia virus. A disease which leaves him babbling incomprehensible gibberish. Said disease was left in a booby trap planted by Bajoran terrorists during the early construction of DS9.
And the virus is spreading. Not helped by Quark. Who with a malfunctioning replicator killing his business decides to use a replicator in an empty set of crew quarters to provide his menu. Thanks to his boneheaded move, the aphasia virus has been spread throughout the station all the faster. And with O'Brien suffering a heavy fever, it's become apparent this virus is fatal.
Doing a little digging, Kira traces the disease back to it's creator. A Bajoran terrorist named Dekon Elig. Problem is, he's dead. Killed trying to escape Cardassian confinement. With that lead a dead-end, she seeks out Surmak Ren. The doctor who signed Dekon's death certificate. But at the first mention of the virus, he terminates connection.
Almost all of DS9 has been infected. Only Sisko, Odo, and Quark remain unaffected. With Kira leaving to "persuade" doctor Surmak to assist her, Sisko and Odo deal with another problem: A panicking cargo captain named Jaheel. With his entire crew infected, he attempts to leave the station. But Sisko insists he can't be risked spreading the virus. This doesn't convince Jaheel, who fries his ship trying to tear loose from the docking ring. Now he's incapacitated, and his ship is a ticking time bomb about to take the docking ring with it.
Beaming Surmak straight from his office to a Runabout, Kira reveals to the good doctor that she's infected. And now he is too. This more than convinces him to get working an an antidote.
Sisko finally gives in to the virus, leaving Odo alone at Ops. Enter Quark, who works the transporter for Odo so he can rescue Jaheel and jettison his ship before it explodes.
With that, the virus is cured and life aboard DS9 returns to normal.