"The Empress of Mars" seems to have started the Peter Capaldi victory tour. The proper season with the overlying arc of love and family ended with the monks and finally we have at least one proper Doctor Who episode. There is no long monologue prefacing this episode. There are no basic questions from Bill. It simply jumps right into the action and has witty banter between the Doctor and his companion. 
First, the Doctor takes his companions on essentially a field trip to NASA. Just dropping into a major security area for fun apparently. Then we jump to Mars with essentially no plan. Just like 9, he is making it up as he goes along. In meeting the Ice Warrior "Friday", the Doctor shows profound respect and sadness as well as his constant distaste for army types who shoot first and conquer that which is not theirs. In an interesting switch, the humans are now the aggressors and invaders of a planet and he treats them in much the same way as he treats invaders of earth.
Nardole is kidnapped by the Tardis, thus removing the quick and easy solution and added a wrinkle to the Missy subplot. In his desperation to save the Doctor he is forced to bring her out of the vault.
In an interesting comment on group dynamics, the aggressive second in command (some may say "bully" even) is proven to be selfish and insecure while the "coward" ends up being what a leader should be. With his surviving 2 executions, it would've been a nice surprise had he ended up being Captain Jack!
We end with a truly awesome Easter egg as Alpha Centauria contacts the Martians and a happy ending is celebrated by all... until the Tardis returns with Missy at the helm. Let the cliffhangers begin.
I hope that we continue seeing characters from the classic era as Capaldi's time comes to a close. This episode was a very nice beginning of the end, without any "Wow, that was awesome!" moments I can't score it perfectly, but it definitely rates 4 (if I may 4 1/2) Tardises out of five.