This steely sense of resolve has become a hallmark of Guillem’s career: she invoked it when she abruptly left the Paris Opera Ballet for the Royal Ballet in 1989—a decision Le Monde deemed “a national catastrophe” at the time—and again in the mid aughts, when she departed the ballet world altogether and embarked on a contemporary career under the stewardship of Sadler’s Wells. Guillem's resoluteness has informed her reputation, infamously earning her the sobriquet 'Mademoiselle Non' during her RB years, when she (in her own words) refused to be “be dependent, be told you do this, you do that.” It's also infiltrated the very fabric of her dancing, particularly in these last few years as she’s transitioned from superstar classical ballerina to darling of the contemporary scene. She moves freely and delicately to be sure, but a certain obstinacy underpins her every motion, a trenchant refusal to produce any steps that fall short of perfect. Years of classical ballet have drilled into her an indelible and unflappable sense of control, and she's crafted an exquisite brand of contemporary dance out of it.

This control is front and centre in “Life In Progress,” the programme assembled to mark Guillem’s impending retirement. The title is telling: her departure doesn’t just mark the close of one chapter but hails the start of new one, though what this new chapter will be even Guillem doesn’t know. (If last year's revival of Sacred Monsters is anything to go by, language classes are likely to figure in.) While she's chosen to leave the stage relatively quietly, she’s not doing it particularly quickly: “Life in Progress” started touring in May, and the final curtain doesn't fall until December, in Japan.

The programme sees Guillem pair up with three celebrated contemporary choreographers—Akram Khan, Russell Maliphant and Mats Ek—and perform a piece choreographed by each. Khan and Ek have each furnished a solo, while Guillem duets with La Scala soloist Emanuela Montanari for Maliphant’s offering.

Tricky stage effects are the order of the day here, from the ornate mechanical tree planted in Khan’s piece to the complicated lights in Maliphant’s and the beguiling video screen Ek's employs. Guillem certainly needs no accoutrement to shine, but these features were an exciting complement to her performance, and lent a sense of occasion to the production.

Khan’s “Technê” won me over from the start with the aforementioned tree, a glittering ornament wreathed in bright white light. Guillem slithers and crouches around it, her hunched form a sharp contrast to the tree’s upright branches. She’s rarely airborne in the grounded piece, but viewers are treated to some of her trademark sky-high extensions. She doesn't so much dance on the stage as with it, and the piece feels all the more organic for it, as if her body itself has been borne of the same soil as the tree. A beautiful, menacing score of vocal gusts accompanies, the musicians shrouded in darkness upstage.

“Duo,” choreographed by William Forsythe and performed by Brigel Gjoke and Ridley Watts, provided a brief interlude before Guillem's next performance. It's a shame Forsythe didn't choreograph on Guillem herself for this show—her casting in his fiery 1987 ballet “In the Middle, Somewhat Elevated” is legendary—but “Duo” has long been a crowd pleaser, and Gjoke and Watts proved more than capable subjects for its complicated pacing (both are, after all, members of Forsythe's soon-to-be-former company). “Duo” bends and challenges the concept of time, the dancers invoking images of pendulums with their arms as they chase a series of trickily cadenced phrases. The programme notes mention “a clock composed of two dancers,” but this timepiece is more Dalí than Big Ben: even with a strident piano score shaping the rhythm, it's a difficult piece to grasp musically, though an easy one to appreciate aesthetically—Watts and Gjoke's terrific communication and beautiful turns make sure of that.

I found Russell Maliphant's “Here & After” marvellously crafted but a tad too familiar for my taste: something about the elaborate lighting and slow-moving choreography—classic Maliphant territory—feels backward rather than forward-looking (not an inappropriate approach in and of itself, though “Life in Progress” seems more geared towards celebrating Guillem's future than commemorating her past). Emanuela Montanari proved a fine match for Guillem, the two achieving a near-perfect unison in both their timing and posture. The first half of the piece is full of smooth, sculpted movements, the dancers eschewing sharp motions even as the music intensifies; the second half ushers in a tempest of punching arms and extensions complemented by blaring rock chords (and in the final moments, a high-pitched yodel). The partnerwork livens up pleasingly as the work progresses: there's weight-bearing and clenched hands, nimble limbs and an impish sense of camaraderie, like Guillem and Montanari are bonded by a shared, fantastically delicious secret.

There's less sass, though no less vigour, in Mats Ek's charismatic “Bye,” a solo the Swedish dancemaker created for Guillem in 2011. The piece features a wondrously clever video screen that deftly flits between recordings and live projections of Guillem, mingling the images so that it appears like she's dancing with her own thoughts. Her brightly coloured cardigan and skirt call to mind a middle-aged woman and a young girl at once, a duality the choreography furthers, mixing childish skips with mature gazes of longing. The multifaceted piece samples a wide array of styles—there are headstands, vaudevillian jigs, jazzy slides, huge balletic leaps—and Guillem breezes through them all, a reminder of how very versatile and intelligent a dancer she is. I was not alone in tearing up at the final scene, in which Guillem casts the audience a mournful glance before disappearing into a crowd of people on screen. The fading light, the melancholic piano music, Guillem's heartbreaking pause—all point to the close of a truly wonderful day.

The dance world isn't just losing a star with Guillem's retirement; it’s losing a master. Adieu, Sylvie, and merci.