This volume contains the five novels of the SIR EDWARD LEITHEN collection.
Leithen -a character created by English writer John Buchan-, is a Scottish barrister and a Tory politician (and MP) and, at one point, an Attorney General, who gets involved in international mysteries and adventures.
The five novels are:
The Power-House
John Macnab
The Dancing Floor
The Gap in the Curtain
Sick Heart River