"I can give you a couple of hours," assented Collison. "I'm already curious—especially if any discovery we can make tends to throw light on the mystery of Hannaford's death. Pity the police haven't got hold of the man who was with him," he added, glancing at Hetherwick. "I suppose you could identify him?"
"Unless he's an absolute adept at disguising himself, yes—positively!" replied Hetherwick. "He was a noticeable man."
An hour later the three men drove up to a house which stood a little way out of the town, on the edge of the moorland that stretched towards the great range of hills on the west. The house, an old-fashioned, solitary place, was empty, save for a caretaker who had been installed in its back rooms to keep it aired and to show it to possible tenants. The laboratory, a stone-walled, timber-roofed shed at the end of the garden, had never been opened, said the caretaker, since Mr. Hannaford locked it up and left it. But the key was speedily forthcoming, and the three visitors entered and looked round, each with different valuings of what he saw.
The whole place was a wilderness of litter and untidiness. Whatever Hannaford had possessed in the way of laboratory plant and appliances had been removed, and now there was little but rubbish—glass, whole and broken, paper, derelict boxes and crates, odds and ends of wreckage—to look at. But the analytical chemist glanced about him with a knowing eye, examining bottles and boxes, picking up a thing here and another there, and before long he turned to his companions with a laugh, pointing at the same time to a table in a corner which was covered with and dust-lined pots.
"It's very easy to see what Hannaford was after!" he said. "He's been trying to evolve a new ink!"
"Ink!" exclaimed Hollis incredulously. "Aren't there plenty of inks on the market?"
"No end!" agreed Collison with another laugh, and again pointing to the table. "These are specimens of all the better-known ones—British, of course, for no really decent ink is made elsewhere. But even the very best ink, up to now, isn't perfect. Hannaford perhaps thought, being an amateur, that he could make a better than the known best. Ink!—that's what he's been after. A superior, perfectly-fluid, penetrating, permanent, non-corrosive writing-ink—that's been his notion, a thousand to one! I observe the presence of lots of stuffs that he's used."
He showed them various things, explaining their properties and adding some remarks on the history of the manufacture of writing-inks during the last hundred years.
"Taking it altogether," he concluded, "and in spite of manufacturers' advertisements and boasting, there isn't a really absolutely perfect writing-fluid on the market—that I know of, anyway. If Hannaford thought he could make one, and succeeded, well, I'd be glad to have his formula! Money in it!"
"To the extent of a hundred thousand pounds?" asked Hetherwick, remembering what Rhona had told him. "All that?"