The Leftovers season 3 episode 3 is as polarising as it is captivating

*Spoilers for The Leftovers season 3 follow - you have been warned*

All episodes will be available to view in the UK on Sky Atlantic from 4 July

It's hard to know where exactly to begin with the latest episode of The Leftovers, a gorgeous-looking delve into the mindset of Kevin Garvey Sr (Scott Glenn), a character whose importance has thus far only been italicised but this week emboldened and underlined in permanent marker. Save for the briefest of returns to the Jamison clan in Miracle, this outing was firmly wedged with Garvey Sr who has been in Australia doing... well, preventing the apocalypse.

To casual fans (they do exist), this episode may hint that The Leftovers is going down a route some won't be comfortable with; the diehards will bask in its glow, taking one look at Garvey Sr naked, caked in paint and singing an aboriginal song to the skies without batting an eyelid.

While 'Crazy Whitefella Thinking' - the third of the final season's eight episodes - is a drastic, ahem, departure from the norm, it actually shares the DNA of every standalone episode we've been treated to thus far whether the focus has been placed on Nora (Carrie Coon), Matt (Christopher Eccleston) or Meg (Liv Tyler). It does this while admirably managing to anchor the head-scratching events witnessed at the climax of last week's episode, 'Don't Be Ridiculous' - something The Leftovers does so fluidly it's a wonder this series wasn't created by transcendent deities.

If the episode seems polarising for those simply tuning in to see Theroux dressed in a cop uniform, that's because it's supposed to be - it exists to echo the psyche of its central character whose sanity has been in question ever since we learn he began hearing voices after Departure Day in season one's second episode. This series sheds its feathers weekly, refusing to be hitched to one ride instead adapting itself to whoever it ends up accompanying - a notion further corroborated by Damon Lindelof's decision to use different theme music for each new episode this season - this week? Richard Cheese's version of 'Personal Jesus'.

The main link between the episode's kooky events is Matt Jamison who we learn sent a photocopy (we all remember how Matt loves to photocopy) of the unauthorised biography - AKA the sequel to the Bible - he's been writing about Garvey Sr's son (Justin Theroux). He grows angry after an initial skim of the Reverend's work, confused as to why he has no mention. He knows his son is important, sure, but he believes the work he is doing in Australia to be of the utmost importance: he's protecting the world from apocalyptic floods that'll rain down on the seventh anniversary of the Departure. Furthermore, he doesn't want his son anywhere near there.

It's uncertain whether Garvey Sr views his son, like most others do, as a part of the endgame or a pawn that'll help him achieve what he believes the voices have been leading him to. Among the episode's many painstaking moments we follow the character through (he falls off a roof, gets lobbed out of a car, is bitten by a snake, not unlike a suffering prophet), there are two key moments which serve as wholly crucial in understanding this man - and boy, are they played beautifully by Glenn: one such moment sees Garvey Sr track down Christopher Sunday whom has the final part of the aboriginal song he requires in order to save the world. Through unforeseen events, he fails to acquire the tune - but does eventually end up in the presence of the woman we saw drowning a police chief named Kevin at the end of last week's episode.

Which brings us to the second of those scenes: Garvey Sr meets Grace (Lindsay Duncan, yet another truly incredible female actor in a series that's had several), a woman who has been on her own determined yet destructive journey following Departure Day (it occurred on 15 October in Australia).

She explains how she was away from home when the event occurred and arrived home to find her children had all disappeared - something she could come to terms with believing the Sudden Departure to be the Rapture. Only, her children's bones were tragically found soon after decimating any faith she had remaining. That was until she found a page of scripture telling the story of a police chief named Kevin who has had contact with the afterlife. After locating a man with such credentials nearby, she drowned him, believing this to be her test. But it wasn't a test, Grace tells Garvey Sr who replies that she's wrong - it's merely a case of mistaken identity: she has the wrong Kevin.

Does Garvey Sr have his son in mind when he smirks at Grace? Or does he believe he's been led to Grace because he is the rightful protagonist of the Bible 2? When this character is concerned, unpredictability reigns. In an interview following the episode, 77-year-old Glenn told Vulture how - way back in season one when researching his character - Lindelof told him that that the voices Garvey Sr hears 'never lie to [him]," bringing to bear echoes of Lost character John Locke. Garvey Sr basically goes through Locke's entire storyline in a single episode (right down to his command of torrential rainstorms). That character's belief that fate overcame coincidence was often seen as delusional - is Garvey Sr a delusional man? The bigger question to ask is will we ever truly know? If the seventh anniversary of Departure Day rolls around and no apocalypse arrives, this episode will be reflected upon rather differently.

To quote the above character: 'crazy people don't know they're going crazy - they think they're getting saner." Right now, Garvey Sr could be the craziest character living in The Leftovers' world - and yet, despite this, it certainly seems like he's onto something.

The Leftovers airs in the US on HBO every Sunday and all episodes will be available to view in the UK on Sky Atlantic on 4 July