Mainline to the Mountains of Madness is an intense combat scenario with novel mechanics that scale the difficulty to the group size. It is the fifth scenario in the Betrayal at the Mountains of Madness campaign, a player-made cycle for Arkham Horror: The Card Game.
This article contains minimal spoilers for the scenario and implicit spoilers for earlier scenarios. If you’d rather play it without any spoilers, you can find a Tabletop Simulator mod here.
“Indeed, I was completely in the dark as to the action that made our platform move so rapidly – it was Peters who had known how to engage whatever mechanism propelled us. The mechanism of the platform required no effort on our part, and the walls rushed by too fast for examination. Blackness surrounded us, cut only by the wan, spectral light of our lamp. Peters squatted, a dark and frightening shape at the other end of the platform.“
-Charles and Janyce Engan, Beyond the Mountains of Madness
Under the Continent of Madness
William Dyer left a detailed record of his explorations in and under the city of the Elder Things, but the impossible megalopolis beyond the mountains of madness is not the only remnant of that ancient, alien race. The whole continent of Antarctica, and the seas beyond, are riddled with their ruins and tunnels.
Nearly two thousand miles away from the city, on the other side of the continent where the Filchner Ice Shelf meets the rock of the land, the investigators are pursuing a party of elder things and their human captives, being carried away to God knows what terrible fate. They pursue them underground into an artificial and strangely warm set of tunnels. Inside they find – somewhat incongruously – something that strongly resembles a train station, complete with floating stone platforms reminiscent of flatbed train cars.
With the aliens ahead of them, the investigators board their own train and set out. If this line truly runs all the way to the city, at the incredible speed it travels it could take as little as twelve hours to cross the continent. These ancient tunnels are not empty though, and as the train slows down to pass other platforms, threats as happy to prey on each other as the investigators may board. Even worse, from behind comes the sound of music – more specifically, Ride of the Valkyries. The Nazis are coming!
This scenario focuses on the new rival keyword, which causes enemies with a history of enmity to fight with each other. You can a find a full, spoiler-free article explaining the keyword here. The Star Chamber have dispatched specialised hunters to control the stygian monstrosities that are flourishing in the warm environment, while the shoggoths still consider this their territory will defend it aggressively. Taking advantage of the hostilities between the different enemies that board the train could be crucial to your success.
Battling monsters aren’t the only thing the investigators need to contend with. The alien train is powered by arcane technology, represented by the Crystal Cache at the back of the train and the Control Cabinet at the front. Investigators must carry clues from the back to the front in order to keep the train moving (represented here by lowering the doom total). If they fail to keep up, the scenario will come to an abrupt end.
Exacerbating this is a novel group size scaling mechanism – the train is composed of a number of locations equal to the number of players, making it longer as the group gets larger. In solo, the back and front of the train are the same location, making carrying clues much easier. In four player, there’s a lot of ground to cover and a much longer trip from the cache to the controls. Time for the seeker to really step up their game and show what they can do.
Of course, keeping the engines running won’t win the scenario, it’ll just stop you from losing. The act deck proceeds at its own steady pace – one clue per turn, one turn per hour as the train races onwards through the dark to reach its final destination.
How to Play
Mainline to the Mountains of Madness is available to play now via Tabletop Simulator.