Around 10 a.m. on 18 March, Norri's patrol reached the tree line on Kaitatunturi. Koivunen remembered the temperature as roughly minus 15°C. Norri climbed higher with two men to observe a road, leaving the others among the trees. As they prepared tea, gunfire erupted. Soviet skiers were trying to cut off their retreat.
The Finns escaped westwards under fire, sometimes with the enemy just a few dozen metres behind. Koivunen took his turn breaking a trail through snow deep enough to swallow his skis to knee level. After hours of effort he was close to collapse. He reached for Pervitin, a powerful methamphetamine-based stimulant carried for the whole patrol, intending to take one tablet. Several stuck to his glove, and he swallowed them all without stopping.
At first he felt a sudden rush of strength. Then the landscape seemed to change shape and his memory broke down. His comrades later told him that his behaviour had become dangerous and that they had removed the magazines from his submachine gun. Koivunen eventually calculated that he had swallowed the unit's entire supply, approximately 30 tablets. That number is his retrospective estimate, not an independently confirmed dosage.
The map pin uses Gora Kayta, a plausible present-day counterpart of historical Kaitatunturi. Neither the exact tree-line position nor the pill-taking location is verified. The photograph shows Pervitin in a modern museum exhibition, not Koivunen's personal supply.