s "whack" Bob was destined never to have.

They again went on duty in the trenches. The day of the great
offensive was approaching.

Suddenly a shot rang out in the sector near the three Motor Boys. They
started, and Ned exclaimed:

"Can that be the signal for the attack?"

"No, it doesn't begin until to-morrow," said Jerry. "That's one of our
own men. Guess his rifle went off by accident."

There was a little excitement, but what had caused it the boys could
not learn at the time, as they must stay at their posts. But a little
later, when their lieutenant came through the trench, Ned, saluting,
asked:

"Did one of our sharpshooters get a Hun, Sir?"

"No," was the answer. "It wasn't that. Private Nixon was shot."

"Noddy Nixon shot!" gasped Bob. "How?"

"S. I. W.," was the terse reply of the officer, as he passed on.

CHAPTER XXV

THE BLACK BOX

The three chums, standing in the wet and muddy trench, looked at one
another as this significant remark was made. Bob either did not catch
what was said, or did not understand, for he asked his companions:

"What did he say?"

"S. I. W.," repeated Jerry.

"Self-inflicted wound," translated Ned. "So Noddy Nixon did that to
himself to get out of the big battle! Well, it's just like the coward!
I'm glad he isn't in our company!"

"So am I," added Jerry.

"Self-inflicted wound," repeated Bob.

"Well, he's out of the fighting now," declared Ned, "though he'll have
the worst time he ever had in his life. He'd better be dead by a Hun
shell."

Silence fell upon the three in the trench while, not far from them,
they could hear the commotion caused as Noddy was taken away to a
hospital. And there, for some time, he remained safely if not
comfortably in bed, while his companions endured the mud and the
blood of the trenches, meeting death and wounds, or just escaping them
by a hair's breadth to drive back the hordes of the Boches.

But over Noddy's cot, and over that of several men on either side of
him was a placard with the significant letters:

_S. I. W._

"Self-inflicted wound." One of the most terrible tragedies of the
war--more tragic, even, than the death of the gallant boys on the day
the armistice was signed, yes, within an hour of it. For those letters
indicated a disgrace that seldom, if ever, could be wiped out.

Briefly it meant that a soldier afraid of going into action with his
comrades, went to some secluded