The Khodunki is a mechanical manned war-machine that Passepartout and Fogg can discover while riding the train from Krasnovodsk to Herat. The Russians riding aboard said train will tell Passepartout a secret, which unlocks the route running from Herat to Waltair. The journey takes 6 days, costs more than a thousand pounds, and has a considerable toll on Fogg's health.
After a few days of traveling, Passepartout will become uncomfortable with some of the other members of the Russian invasion force. At one point he may even be left behind by the rest of the group including Fogg, forced to catch up with them over the course of a day. Passepartout will be prompted with the option to go with Fogg and abandon the Russians. After planning escape, simply wait for the other walkers in the convoy to start moving after a rest stop. You are then prompted with a choice: Climb ravine immediately, or look for a pass. Climbing the ravine will lead Passepartout and Fogg to the walking city of Agra after three days of travel, and looking for a pass will take them to Delhi instead.