HS2 is a planned network of high speed railways which will connect English cities. It will cost over £80 billion and will never run to Scotland. The UK Treasury determined before the 2015 general election that it was a national UK project and that Scotland would therefore have to pay its share of it (like we did for the London Olympics). They got away with this because our then MPs were mostly Unionists and were happy for Scotland to subsidise England. This all changed in 2015 when we elected 56 Scottish MPs and the Treasury had to back down. HS2 is now considered an English project which means that Scotland will get its share of the cost back via the Barnett formula. An £8 billion bonus just for voting in Scottish MPs.
The moral is: If you are Scottish, do not elect Unionist politicians.