He could easily take a handbag filled with explosive material into the
café. He was known there, but not as a friend of Hertzog's. He was a
customer and a tenant, therefore doubly safe. But he could not leave
the bag there, and if he stayed with it his revenge would rebound on
himself. He could hand the bag to the waiter saying he would call for
it again, but the waiter would naturally wonder why he did not give it
to the _concierge_, and have it sent to his rooms; besides, the
_garçon_ was wildly suspicious. The waiter felt his unfortunate
position. He dare not leave the Café Vernon, for he now knew that he
was a marked man. At the Vernon he had police protection, while if he
went anywhere else he would have no more safeguard than any other
citizen; so he stayed on at the Vernon, such a course being, he
thought, the least of two evils. But he watched every incomer much more
sharply than did the policeman.

Dupré also realised that there was another difficulty about the handbag
scheme. The dynamite must be set off either by a fuse or by clockwork
machinery. A fuse caused smoke, and the moment a man touched a bag
containing clockwork his hand felt the thrill of moving machinery. A
man who hears for the first time the buzz of the rattlesnake's signal,
like the shaking of dry peas in a pod, springs instinctively aside,
even though he knows nothing of snakes. How much more, therefore, would
a suspicious waiter, whose nerves were all alert for the soft, deadly
purr of dynamite mechanism, spoil everything the moment his hand
touched the bag? Yes, Dupré reluctantly admitted to himself, the
handbag theory was not practical. It led to either self-destruction or
prison.

What then was the next thing, as fuse or mechanism were unavailable?
There was the bomb that exploded when it struck, and Dupré had himself