Martin and the gang reach St. Hubert and hop into a rowboat to go to the island. The ship they're on won't go anywhere near St. Hubert, since everyone knows the island is quarantined. When they head toward shore, Martin gives Leora one last chance to go back to the ship, but she refuses.
They reach the port and talk to the doctor who's waiting for them. The island has more than a thousand cases of plague and more than a million rats spreading the disease around.
When they reach their hotel, they learn that none of the bellhops are coming into work anymore, so they all have to take their own bags.
After they meet the island's surgeon general (the dude who wouldn't admit that there was plague on the island), an old acquaintance from Martin's past shows up. It's none other than Ira Hinkley, Martin's old Bible-thumping buddy from med school.
The Surgeon General leads them around the island. Everyone is holed up in their houses, and an atmosphere of death hangs over everything.
While Martin gets to work on preparing vaccines, Sondelius makes it his mission to kill as many rats on St. Hubert as he possibly can. He even takes control of government offices to command as many rat-killers as he can.
As the Surgeon General loses his nerve, Sondelius steps in and basically takes over administration of the island.