Standard situation in movies: hero lost, but villain not killing him. Some time later situation changes and because of that hero starting to have way to escape and fight back.
In Go opponent usually don’t actually capture your dead group because instead its possible to get more additional territory in other place. This is a risk and your opponent may underestimate it. When more and more new different stones appear around your dead group, opponent may miss moment when they have to capture it. And then you would strike back.
My attack on top right group was total fail. But I didn’t resign.
I created distraction at the left.
32 moves later:
its still possible to capture my group:
but…
…