I don't know how City Mapper is getting that number to be honest. TFL gives 35 minutes, and that includes 5 minutes for walking out the tube at Kings Cross. Th

I don't know how City Mapper is getting that number to be honest. TFL gives 35 minutes, and that includes 5 minutes for walking out the tube at Kings Cross. The trick is you have to change at Stockwell onto the Victoria Line. Nb. I did almost this journey every day pre-lockdown and the numbers are accurate for me at least.