So my internet died... might die again... I will try to be useful as I can now.
The heart is an actual heart
just a bit... more. Slightly mechanical slightly magical, and totally gross.
It returned to the literal last place Ox stood on Earth, which was outside of the side-alley entrance, on the steps. So it'll be just laying there in the middle of the alley, the heat it's complaining about 'like fire' is literally because it's in the sun. xD Very anticlimactic I know, but we need to get a move on. Sorry.
As for the door being locked... eh? Does it matter? :P You decide, just charge through, blow it down, or whatever.
In fact none of that matters. The Heart doesn't do 'conversation' it's completely mad, not entirely sentient, and a complete ditz. It likes to make comments about what it sees and knows, but it's so upset now it's kind of paying attention for once. So we're just going to say it will materialize in front of her face with a magic-y woosh. <3