Follow tarmac road up to the cattle grid, then a steady climb before dropping onto the reservoir track past Loch Humphrey, which is fast and runnable.
After the 2nd gate turn right along a fenceline, then a flagged section through tussocky bog, before reaching another fast runnable section alongside Greenside Reservoir. Danger - watch out here for rusty metal spikes from old fenceposts.
After crossing Greenside Reservoir dam, there is one final climb up the Slacks before flagged descent down heather slopes, to join the outward route at Kilpatrick Braes.
The final 900 metres are downhill foot-slapping tarmac.