Thank you. The effects of the lockdown here in the UK are clearly making my brain go to dark and isolating places. But the reason this episode stands out for me at the moment is Ada: her bravery, her compassion, her willingness to defy years of mental and physical torment in order to help another soul in need. And of course the Doctor- in his own flighty, eccentric way - repays that debt to her. Their relationship is a twisted yet tender one.