(Omni-Syfy science fiction series, 2012-)

Episode 1:13
Canadian-filmed spin-off from the UK Primeval series - gorier, but with more coherent storylines.
This episode has scenes set in London, but filmed in Vancouver.
The bus used is British. It's Horizon Coach Lines D252, a Daimler Fleetline new as Derby Corporation 252 (CRC252J) in 1970.
As can be seen it's been modified for Canadian sightseeing with an offside entrance, but otherwise is largely in original condition, including a Derby destination blind!

Nice to see Andrew Lee-Potts in action, imported from the original series. D252 also appears in Big Time Movie.