After several weeks of overstuffed episodes that seemed to be steering multiple plot-threads towards something bigger and better, we get 4,722 Hours - a bottle episode entirely dedicated to Simmons ordeal on the alien desert planet.
Flashing back six months, the story begins with Jemma and Fitz arranging their first date, and then Simmons' abduction by the portal.
After a month of subsistence living on the alien world, Jemma is captured by Will Daniels (Dillon Casey), the last survivor of a four-man NASA expedition through the portal back in 2001.
Initially confrontational, eventually the two stranded humans develop a friendship, born out of the mutual desire for survival, with Jemma's constant optimism balanced by Will's pessimism.
Unlike anything we have seen in the two-and-a-half-years of Agents Of S.H.I.E.L.D. so far, 4,722 Hours even earned itself a unique title sequence.
Filmed largely in the surface twilight of the alien world, and carried by the central performances of Elizabeth Henstridge - as Jemma Simmons - and Dillon Casey, this was a stark contrast to the usual team dynamic of the show, isolating one of its leads and letting us see her training and resilience come to the fore.
Not only does 4,722 Hours follow the evolution of the relationship of Jemma and Will, but drops sandstorm-hidden hints to a mysterious alien lifeform - with a definite Doctor Who vibe (is it the space suit?) and possibly directly connected to the planet's "moods" - that stalks anyone who comes through the portal.
There's evidence on the planet that people have been coming through the portal for many, many years, and you have to wonder at (a) Will's reluctance to share this information with Simmons and (b) how he has managed to survive for over a decade?
I don't trust Will, and it's not just because he is a fly in the ointment of the dream pairing of Fitz and Simmons. And what about this murderous enigmatic presence? Is it connected to Will? Is it connected to the Inhumans back on Earth? Is it something to do with Lash?
I, for one, can't wait to find out.