And even as he fought for the entire diagram, he heard the beginning take-off rumble.
"Wait!" he yelled.  "What for me!  You can't..."

There was a flash that turned the world pure white and a mighty invisible wave came swishing out of nowhere and sent him reeling down the street, falling as he reeled.  He was skidding on the cobblestones and sparks were flying as his metal scraped along the stone.  The whiteness reached a brilliance that almost blinded him and then it faded swiftly and the world was dark.

He brought up against a wall of some sort, clanging as he hit, and he lay there, blind from the brilliance of the flash, while his mind went scurrying down the trail of the diagram.
The diagram, he thought - why should he have seen a diagram of the ship he'd ridden through space, a diagram that had shown an injector out of whack?  And how could he, of all robots, recognize an injector, let alone know there was something wrong with it.  It had been a joke back home, among the Barringtons, that he, a mechanical thing himself, should have no aptitude at all for mechanical contraptions.  And he could have saved those people and the ship - he could have saved them all if he'd immediately recognized the significance of the diagram.  But he'd been too slow and stupid and now they all were dead.

The darkness had receded from his eyes and he could see again and he got slowly to his feet, feeling himself all over to see how badly he was hurt.  Except for a dent or two, he seemed to be all right.

There were robots running in the street, heading for the spaceport, where a dozen fires were burning and where sheds and other structures had been flattened by the blast.

Someone tugged at his elbow and he turned around.  It was the ancient robot.

"You're the lucky one," the ancient robot said.  "You got off it just in time."