I had thought it to be the blind man’s trumpet, so to speak, summoning his crew to the assault, but I now found that it was a signal from the hillside towards the hamlet, and from its effect upon the buccaneers, a signal to warn them of approaching danger.
"That’s a summons, mate.
There are no more uses of "summon" in the book.
Show samples from other sources
I was summoned to the principal’s office.
I summoned all my courage and walked into the room.