Simple question: correct way to save traces?

So, I tried specifying an empty folder to save into within the same jupyter notebook directory with directory=, and specified overwrite=True, and consequently the folder becomes populated with two separate sub-folders, I assume corresponding to both of my chains.

However, how do I load these back into a singular trace within my Python session? pm.load_trace keeps giving me "list index out of range" errors, could you tell me how to fix this?