Two separate questions, same work.
The protagonist of this work is a 20-year-old male who recently experienced a moderate TBI. I know a reasonable amount academically about TBIs/recovery/long-term disability, but almost nothing about the actual practical side of where you are and what you do during.
I have it in my head that he's about a month out from the injury. He has significant cognitive dysfunction, but it isn't necessarily noticeable because of how high-functioning he was before (e.g. effortlessly getting high grades at university); he feels completely scrambled from the inside, but would (in the short term) pass as neurotypical to someone who didn't know him before. He dissociates frequently and has massive gaps in his memory, both in the traditional TBI short-term sense (no recollection of the accident or the time before/after) and in the long term after (the massive time/memory gaps he keeps experiencing and can't account for are a plot point). Mild hemiparesis, personality changes that are only just becoming clear. Seizures that aren't tonic-clonic, but I haven't yet narrowed down exactly what they are. The injury was severe enough to require neurosurgery; he was in a car crash and possibly has other injuries, but they were more minor and not plot-relevant if he did. The timeline is the part of this I'm least confident about, and it's possible I have it massively too short (or long).
His family live in a different state and would have a hard time supporting him for a number of reasons, not to mention that he's very clear he doesn't want to go back home. His friends/flatmates and girlfriend have very little contact to him up to this point and only a vague sense of where he actually physically is. By the time the plot kicks in, 'where he actually physically is' is his ex-girlfriend's basement with a famous actress tied up in the corner and no idea what happened in the last 24 hours. But where was he before?
Is he still inpatient? That's what I had at first, but realized long-term neuro hospitalization of someone who's conscious and able to perform ADLs seems implausible. He's been talking (texting) with his girlfriend, who's visited a couple times, but he's had some kind of limit (self-imposed? schedule problems?) on visitors overall. He needs to be able to escape this place somehow, and his ex (who is severely mentally ill and incapable of self-care) needs to be able to find him in it -- hence why I originally wanted him to still be in hospital, where she could be in psych. (Outside the hospital, she lives with her parents and can't drive.)
It seems most plausible he's in some kind of rehabilitation situation, but I also don't know that'd be inpatient for someone who presents relatively high-functioning, even if it's an illusion. I'd really prefer he not be in an outpatient environment. Considering his outpatient environment is either 'shitty student flat/party house' or 'uncaring bogan family several hundred kilometres away', it's possible he winds up inpatient over that, but it's equally-or-more possible the system just shrugs and throws him to the wolves.
The famous actress (fictional) tied up in the basement where he comes to is a Melbourne native, headed home to visit her family for some-reason-or-other. I've been to Melbourne multiple times and will be moving there long-term in the near future, but I haven't spent a lot of time playing around in the suburbs and don't have an intuitive sense of what they're like yet.
She's from a working- to lower-middle-class background. I grew up in Adelaide's northeastern suburbs, most of which are along those lines (some are significantly higher or lower) but a few of which developed much worse reputations than they really deserved, so I've been reading suburb stereotype discussions with an eye towards the middle-class tendency to exaggerate working-class woes.
I know the house where the protagonist's ex lives is in Box Hill. I also know the actress's family lives a significant geographic distance from there -- when she disappears, the search is centered on the area and nobody bothers to look that far away from it until she's been gone for quite a while. Again, his ex can't drive legally speaking and he just almost died in a car crash, so they're likely limited to 'far-off suburbs still accessible-ish by public transit'. (I assume this will require at least one bus/train change.) Considering he wasn't in an entirely rational state of mind at the time, though, it's possible he (or she) drove anyway.
I know the suburbs of Melbourne and Geelong have a lot of overlap at this point, and I'm not ruling out the latter.