By 1943 the Germans depended on a handful of railway arteries to move supplies from Western Europe toward their forces in North Africa and the Eastern Mediterranean. Three viaducts in Greece were bottlenecks in that chain. One — the Gorgopotamos — had already been blown up in November 1942 by SOE agents working alongside Greek partisans, an operation celebrated across the Allied world. The Asopos viaduct, spanning a gorge near Lamia, was the next priority. Brigadier Myers ordered its destruction in May 1943, partly to support Operation Animals — a coordinated deception campaign timed to mislead the Germans before the Allied invasion of Sicily. The order was straightforward. What lay between the order and its execution was not.

The Asopos gorge is sheer-walled and cold even in early summer, its river loud enough to drown conversation. The viaduct sat at its base, guarded by a fortified position above. Captain Edmonds established a forward headquarters in the remote village of Anatoli and sent his team to reconnoiter. Their first attempt to descend in early June failed. Without the right equipment — ropes, waders, climbing gear — the waterfall-laced cliffs were impassable. The team retreated, cold and demoralized. They regrouped and waited for supplies. New Zealand Lieutenant Donald Stott and two comrades — Mutch and Khouri — made a second push on June 15. They felled a tree across a waterfall to bridge it, forced their way through freezing water, and after days in the gorge emerged 100 yards from the viaduct itself. Stott could see German workers reinforcing the structure. He pulled back, found steps cut into the rock by workers, and sent word to Edmonds: they had a way in.

On June 18 the full team assembled beneath the viaduct. They worked in near-silence — the roar of the river helped mask their movements, but a loose rivet that clattered down the metalwork froze them where they stood. A German searchlight swept across the gorge. They waited. It passed. After two hours the charges were set, fitted with time-pencil detonators that they crushed before beginning the climb back out. The ascent was brutal. Exhausted and freezing, they checked their watches obsessively as the deadline passed with no explosion. Then a white flash lit the gorge — soundless to them over the river, but unmistakable. The Asopos viaduct was gone.

The Germans initially suspected an accident. They executed several of their own guards. Only five days later, when a rope ladder made of parachute cord was found anchored above the gorge, did they understand what had happened. Their attempt to rebuild proved disastrous: the replacement framework collapsed during construction, killing the supervising engineer and a number of workers. The disruption to rail traffic through central Greece was exactly what British planners had hoped for, and the timing — coinciding with the lead-up to the Sicily landings — compounded its value. Stott was awarded the Distinguished Service Order. Edmonds's officer Gordon-Creed also received the DSO. Scott and McIntyre received the Military Cross; Mutch the Military Medal; Khouri a bar to his Military Medal. The team's achievements were detailed years later in Roger Field's book Rogue Male.

The Asopos gorge still cuts through the landscape of Phthiotis in much the same way it did in 1943 — narrow, steep, and carrying snowmelt from the flanks of Mount Oeta. The railway line that the team targeted remains part of the Greek rail network. Nothing about the terrain makes Operation Washing look easy; if anything, standing above the gorge today makes the audacity of the descent more legible. These were men who went somewhere the landscape itself said was closed, and they went there twice.