 How were Jig and Bucky attacked by the Vapor snakes?
The Blue Behemoth By LEIGH BRACKETT Shannon's Imperial Circus was a jinxed space-carny leased for a mysterious tour of the inner worlds. It made a one-night pitch on a Venusian swamp-town—to find that death stalked it from the jungle in a tiny ball of flame. I've wet-nursed Shannon's Imperial Circus around the Triangle for eleven years, and I know. Bucky Shannon walked out into the glare of the light at the entrance to the roped-off space around the main lock. It grates on a man's pride to have to sneak in and out of his own property through the sewage lock.
 They had been released by someone on purpose
 They had been released by someone on purpose  Bucky had released them while inebriated  They had gone into the wrong enclosure.  They had escaped their tanks in search of food.