It was the sequence of victims which puzzled them all.  As far as Tau had been able to discover Mura and Kosti had nothing much in common except that they were crewmates on the same spacer.  They did not bunk in the same section, their fields of labor were totally different, they had no special food or drink tastes in common, they were not even of the same race.  Frank Mura was one of the few descendants of a mysterious (or now mysterious) people who had had their home on a series of islands in one of Terra’s seas, islands which almost a hundred years before had been swallowed up in a series of world-rending quakes—­Japan was the ancient name of that nation.  While Karl Kosti had come from the once thickly populated land masses half the planet away which had borne the geographical name of “Europe.”  No, all the way along the two victims had only very general meeting points—­they both shipped on the Solar Queen and they were both of Terran birth.

Tau stirred and sat up, blinking bemusedly at Dane, then pushed back his wiry black hair and assumed a measure of alertness.  Dane dropped the now purring cat in the Medic’s lap and in a few sentences outlined his suspicion.  Tau’s hands closed about Sinbad.

“There’s a chance in that—­” He looked a little less beat and he drank thirstily from the mug Dane gave him for the second time.  Then he hurried out with Sinbad under one arm—­bound for his lab.

Dane slicked up the galley, trying to put things away as neatly as Mura kept them.  He didn’t have much faith in the Sinbad lead, but in this case everything must be checked out.

When the Medic did not appear during the rest of the ship’s day Dane was not greatly concerned.  But he was alerted to trouble when Ali came in with an inquiry and a complaint.

“Seen anything of Craig?”

“He’s in the lab,” Dane answered.

“He didn’t answer my knock,” Ali protested.  “And Weeks says he hasn’t been in to see Karl all day—­”

That did catch Dane’s attention.  Had his half hunch been right?  Was Tau on the trail of a discovery which had kept him chained to the lab?  But it wasn’t like the Medic not to look in on his patients.

“You’re sure he isn’t in the lab?”

“I told you that he didn’t answer my knock.  I didn’t open the panel—­” But now Ali was already in the corridor heading back the way he had come, with Dane on his heels, an unwelcome explanation for that silence in both their minds.  And their fears were reinforced by what they heard as they approached the panel—­a low moan wrung out of unbearable pain.  Dane thrust the sliding door open.

Tau had slipped from his stool to the floor.  His hands were at his head which rolled from side to side as if he were trying to quiet some agony.  Dane stripped down the Medic’s under tunic.  There was no need to make a careful examination, in the hollow of Craig Tau’s throat was the tell-tale red blotch.