When Bill Barnett’s party of five arrived they found some dozen members of the Observatory already assembled, including Jensen, Rogers, Emerson, and Harvey Smith. A blackboard had been fitted up and a screen and lantern for showing slides. The only member of Barnett’s party who had to be introduced round was Dave Weichart. Marlowe, who had heard a number of reports of the abilities of this brilliant twenty-seven-year-old physicist, noted that Barnett had evidently done his best to bring a bright boy along.

“The best thing I can do,” began Marlowe, “is to explain things in a chronological way, starting with the plates that Knut Jensen brought to my house last night. When I’ve shown them you’ll see why this emergency meeting was called.”

Emerson, who was working the lantern, put in a slide that Marlowe had made up from Jensen’s first plate, the one taken on the night of 9 December 1963.

“The centre of the dark blob,” went on Marlowe, “is in Right Ascension 5 hours 49 minutes, Declination minus 30 degrees 16 minutes, as near as I can judge.”

“A fine example of a Bok globule,” said Barnett.

“How big is it?”

“About two and a half degrees across.”

There were gasps from several of the astronomers.

“Geoff, you can keep your bottle of whisky,” said Harvey Smith.

“And my crate, too,” added Bill Barnett amidst the general laughter.

“I reckon you’ll be needing the whisky when you see the next plate. Bert, keep rocking the two backwards and forwards, so that we can get some idea of a comparison,” went on Marlowe.

“It’s fantastic,” burst out Rogers, “it looks as if there’s a whole ring of oscillating stars surrounding the cloud. But how could that be?”

“It can’t,” answered Marlowe. “That’s what I saw straight away. Even if we admit the unlikely hypothesis that this cloud is surrounded by a halo of variable stars, it is surely quite inconceivable that they’d all oscillate in phase with each other, all up together as in the first slide, and all down together as in the second.”