In 1881 a British railway entrepreneur, Sir Edward Watkin, and a French contractor Alexandre Lavalley, formed Anglo-French Submarine Railway Company and dug a 1893m tunnel under the Channel from Shakespeare Cliff in Dover, and a 1669m tunnel from Sangatte in France, before the project was abandoned the following year amid security concerns.
This Snowdonia expansion imagines what would have happened next - with one player taking the part of the English builders, and another taking the part of the French, and each armed with their own boring machine, the players must build, dig and lay track from St. Pancras to Paris, being sure to deal with any crises that crop up along the way.