So, this episode that's been written by Mark Gatiss and has Rachel Stirling and Dame Diana Rigg in it and might (if I'm understanding right) be the one that's also got David Warner in it) also...
...has Madame Vastra in it (and one would hope Jenny), as well, from the location photos that SFX have published) a Sontaran dressed as a Victorian butler.
My main, overriding feeling about this - apart from yay!ness at the mere return of Vastra and Jenny (I refer you to lizardladylove for your fix of, well, Lizard/Lady love) - is...
Hang on, Rachel Stirling in the same episode as Vastra and Jenny.
lizardladylove for your fix of, well, Lizard/Lady love) - is...