Board Thread:Whoniverse Discussion/@comment-24121492-20150926193433/@comment-24121492-20150928100042

If I had one complaint about this episode, is how come the Doctor knew and used the sewers to his advantage?

How did he know about the sewers? And even if he did know, how did he know Colony Saarf would take him to Skaro?

"SKARO! You bought me to Skaro!!". He was clearly surprised to be where he was.