Remember what 11 said in Town Called Mercy ?. Something like "Today I honour the victims his (Jax) the masters, ... all the people who have died because of my mercy!".
Doctor really should deal with Missy when he has the chance not let her escape or get the better of him (again!). I know they have a long and complicated history. It will not be a pleasant or easy thing to do. However that does not mean he shouldn't do it.
Doctor is the only other time lord around. AS the only person who has the ability to stop her one could argue it is his duty to stop her hurting or kill anymore innocent souls human or otherwise.
Plus how would he explain to Clara and Kate that he has let her get away with her crimes including murdering Osgood when he could bring her to justice ?.
Hopefully S9 will be on our screens end of August and we can see what happens next. Got a feeling she will be in the finale too.

Doctor really should deal with Missy when he has the chance not let her escape or get the better of him (again!). I know they have a long and complicated history. It will not be a pleasant or easy thing to do. However that does not mean he shouldn't do it.
Doctor is the only other time lord around. AS the only person who has the ability to stop her one could argue it is his duty to stop her hurting or kill anymore innocent souls human or otherwise.
Plus how would he explain to Clara and Kate that he has let her get away with her crimes including murdering Osgood when he could bring her to justice ?.
Hopefully S9 will be on our screens end of August and we can see what happens next. Got a feeling she will be in the finale too.
Would be such a turnaround, why can The Doctor be angry for something that may not have been her fault if looked into more detail?