If you want the activations at every layer you could register a forward hook on every module and store them in a list with .append(). Naively I’d expect that they would then be in the order in which they executed?
handles = []
variable_storage = []
for module in net.modules():
    handles.append(module.register_forward_hook(lambda input, output: 
                                         variable_storage.push_back(output))