I have tried to search to find the answer to this question but cant find anything relevant.

We are flying LHR-SIN-SYD next Friday in Club World (Managed to somehow get 241 voucher availability on the route last October)

I know we have about a 1.5hr "stop over" in SIN and wondering what happens, I assume we have to leave the plane, if so do we need to take all handluggage with us (obviously wont be leaving valuables behind but do I need to take everything with me). Is there a loumge or something we can go to or is it just a "holding pen"