The mystery in part explained, he did not bother to puzzle out the remainder of it.
Impossible as it seemed, his bag was carried by some living thing.

All that remained for him was to capture the thing, and recover his bag.
The weak light still turned on, he gave chase.
Lad's spirits arose with a bound.

His ruse had succeeded.

He had reawakened in this easily-discouraged chum a new interest in the game.
And he gamboled across the lawn, fairly wriggling with delight.

He did not wish to make his friend lose interest again.