In the next picture, the haze was widening, and rising even higher above the children’s heads. It was beginning to form into tentacular coils, which in the third picture were writhing almost up to the lower branches of the maple tree at the edge of the school yard.

The fourth and the fifth photographs were the most alarming. They showed a towering beast, draped with scores of curling arms, like a kind of gaseous squid, high above the children. Although it was faceless and formless, it possessed a terrible and evil aspect, as if it was formed out of the essence of ancient malevolence. It seemed verminous and unhealthy, and riddled with diseases of the mind and the spirit.

“What is that thing?” asked Neil. “Is that some kind of photographic illusion?”

Mr. Saperstein replied, “No trick, Mr. Fenner. They were developed for me by Charlie Keynes down at the newspaper office. He does all my prints. He swears blind that this is the way they came out.”

“Maybe the light got into the film, you know, and fogged it,” suggested Neil.

Mr. Saperstein shook his head. “That’s not fogging, Mr. Fenner. Any amateur could tell you that.”

“You’re right, Mr. Saperstein,” concurred Singing Rock, quietly. “These pictures are not fake.”

“But how can you tell?” asked Neil. “It must be easy to take an airbrush or something and—”

Singing Rock smiled, and benignly silenced him. “No amount of airbrushing could ever portray what’s on this photograph, Neil, because no artist knows what this creature looks like or what it is. This creature is one of the shapeless ones who guard the threshold between this world and outside. They are messengers of the ethos in which the great old ones have dwelled for more centuries than I could count.

“This thing is a herald, if you can call it that, for Pa-la-kai the demon of blood, and Nashuna the demon of darkness, and for Quul the demon of insanity. Those three, in their turn, are servants of Rhenauz the demon of evil, and Coyote the demon of corruption. Above all these, though, and guarded by a pack of creatures called the Eye Killers, is Ossadagowah, the son of Sadogowah, the demon who can be conjured up but can never be returned, except of his own free will.”

“Then what’s this thing?” asked Harry. “Just a minor-league stooge?”

“In comparison, yes,” said Singing Rock. “Its name is Sak, which simply means ‘the past.’ It is a beast that has existed on this planet for countless millions of years, or so the Algonquian say. Its chosen duty has always been to encourage humans to summon the elder gods, so that the elder gods may devour them as sacrificial gifts, and reward Sak with whatever a beast like that might want as a reward.”

“A gold ball-point pen?” asked Harry. “Who knows what demons want?”