Berlin laughs uncontrollably in where have you gone charming billy because he finds billys death

I believe the answer is: ironic

In the story, Billy was described to have overwhelming fear that he somehows gonna die from an injury so he choose to take careful precautions in his actios.
The ironic part is that Billy become so scared and he died because  of heart attack due to fear rather than injuries.

The will be a : great britain wanted french gold mines