"You think you know me, but you don't," Athos warns in this week's Muskeeters - but by the time the credits have rolled on 'The Return', the audience does know Tom Burke's surly hero a little better.
Burke takes centre stage for this semi-sequel to last year's 'Commodities' - in which the Musketeers took refuge in Athos's derelict family chateau and The Musketeers first delved into his tragic past.
Having drowned his sorrows following last week's dramatic encounter with Milady, Athos is easy prey for kidnappers - and 'The Return' throws us straight into the action, with the swordsman already in their custody.
But these abductors mean Athos no harm - having abandoned his duties as the Comte de la Fère, he's been forcibly returned home by the peasant folk whose pleas he's ignored, ever since he absconded.
Like episode two of this series - 'An Ordinary Man', which saw King Louis lost amongst his people - 'The Return' explores the chasm between noblemen (such as they are) and the less fortunate of France.
Those 'common' folk becomes masters of their own destiny after rising up against the aristocracy, while Athos renounces his title and becomes a champion of the common man - after some considerable cajoling.
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That he resists for so long is in part owing to the spectre of Milady: Athos's early reflections on their romance - which involve the pair frolicking in fields, dressed in white linen - seem tailor-made for YouTube fan edits.
But as Athos retreats from the village to the darker confides of his burnt-out chateau, so too do his memories grow more grim and we glimpse the moment in which Milady slaughtered his brother - ostensibly following an attempted rape.
Even though she's absent from the 'present day' scenes, Maimie McCoy gets to play a more vulnerable, less calculating Milady in the flashbacks, and much light is shed on the character by illustrating the obstacles she's faced in the past.
The wrathful Catherine, Athos's one-time intended and now his brother's widow, was apparently poisoned against Milady from the start - and it's near-impossible to change or prove your worth if never given fair opportunity.
Back in the present, Athos does of course emerge from his self-pitying stupor to take up arms - and just as well, because his nemesis, Baron Renard, is an unabashedly wicked antagonist.
"I used to find a piquancy in struggles and tears," he remarks, being offered the opportunity to force himself on a young woman. "But one grows jaded with such simple pleasures" - it's a part played with camp relish by actor Miles Anderson.
The supporting cast for 'The Return' is comprehensively impressive - though Constance and Anne are absent, the episode compensates somewhat with the introduction of an intriguing new female character in Catherine (Marianne Oldham), who looks set to continue plaguing Athos and friends for a while longer yet.
There's time too for the recent developments in Treville's life to be addressed - he was relieved of his command following the Emilie affair and The Musketeers earns points with me for not immediately returning him to his post.
Instead, a deflated Treville gets back on the horse - literally - by joining the peasants' revolt, his leadership skills clear for all to see as he rouses the peasants with an inspiring speech and later trains them in the art of war.
But 'The Return' belongs to Tom Burke - the episode rests on his shoulders and he more than delivers, allowing Athos's inner torment to reveal itself with a performance that's more demonstrative than his standard.
A stirring adventure, but one with a personal slant that sheds new light on two major Musketeers characters, 'The Return' is another strong outing for the BBC One series this year, more than justifying that third series commission.
