They're to go to the Neretva area of Bosnia to discover why, in recent weeks, every Allied agent parachuted into that area has been captured.
With the April War and the fall of Yugoslavia to Axis forces, the Montenegrin Federalist Party offered to collaborate with the Italian Fascists of Benito Mussolini, demanding a Greater Montenegro from the river of Neretva in Herzegovina to Mata in Albania; it would also include Metohija and Sandžak.
Specifically, there is a town in Bosnia and Herzegovina situated in the wider Neretva valley region (the original homeland of ancient Illyrian people of Ardiaei),called Čapljina, and its name derives from čaplja, which in modern Croatian and Serbian language means 'heron'.
To the North - North-West is Vran mountain with its highest peak on 2.074 meters a.s.l. while on the South - South-East is Čvrsnica mountain with its highest peak Ploča at 2.228 meters a.s.l., South is Čabulja mountain with its highest peak at 1.786 meters a.s.l., in the North - North-East is the Doljanka river and in the East is Grabovica valley that stretches to the Neretva river.
Alistair MacLean's 1968 thriller novel Force 10 From Navarone, subsequently filmed, also brings forth the fight of outnumbered Partisans against Germans and Chetniks, and the blowing up of the Neretva bridge.
Čvrsnica is surrounded by the river Neretva from the east (20 km), its tributaries Doljanka (18 km) from the north and Drežanka (19.8 km) from the south, the Dugo Polje field (12 km) and Vran mountain from west.
Continental Doclea, or Submontana (Podgoria), which was between the rivers of Rama and Morača, consisted of: Onogost, Moratia, Comerniza, Piva, Gerico, Netusini, Guisenio, Com, Debreca, Neretva and Rama.