The latest reports suggest that Marvel's Loki series, which will premiere on Disney+ in spring 2021, will directly set up Taika Waititi's Thor: Love and Thunder. Speaking at San Diego Comic-Con 2019, Marvel Studios president Kevin Feige officially announced the launch of a range of Marvel TV shows that will be exclusive to the Disney+ streaming service. These feature Marvel stars from the big screen, and they're set to tie directly into the movies themselves.
One of the most exciting prospects is Loki, which will see Tom Hiddleston reprise the role of the Trickster God. Avengers: Endgame raised the possibility of Loki's return, with the Avengers unwittingly creating a timeline in which Loki absconded with the Tesseract in 2012. With the MCU set to embrace the Multiverse, it's generally thought the Loki of 2012 could eventually make his way into the main timeline.
The latest reports from FandomWire suggest that these theories are true. The site has acquired a new production logline for the Loki show, which reads: "[Loki] follows Loki after the events in Avengers: Endgame as the trickster uses the power of the Tesseract to travel throughout human history and change historical events." According to their sources, Loki's adventures will end with him emerging in the mainstream MCU - and he'll somehow bring Mjolnir with him, explaining how Jane Foster is able to become the Mighty Thor in Thor: Love and Thunder.
It's worth noting that, at this stage, these reports are still unconfirmed. FandomWire has a mixed reputation, but it's been improving as of late; they proved right about Black Lightning's "Crisis on Infinite Earths" appearance, for example. What's more, this idea matches with the little that's known of the Loki TV series, which is confirmed to feature time travel. It also dovetails perfectly with the MCU's overarching narrative, with the Multiverse increasing in importance and the prospect of Natalie Portman's Jane Foster becoming the female Thor.
But just how does Loki use the Space Stone to travel in time? That's traditionally the province of the Time Stone. A possible solution lies in quantum physics, which argues that time and space are interwoven; if you affect one, then you affect the other. It's possible Loki will figure out how to manipulate spacetime itself with the Tesseract. If this is indeed how Loki travels through time, then presumably he'll arrive in the regular timeline by using the Tesseract as well. That means one of the Infinity Stones could be back in action too.
The prospect of an Infinity Stone's return is far less exciting than the idea Loki will bring Mjolnir with him, of course. Presumably this won't be because he's managed to break the enchantment and lift the hammer; instead, it's more likely he opens a wormhole in Mjolnir's way, or else that an alt-reality Thor unwittingly tosses Mjolnir through a portal. If the latter is the case, then it may well mean Chris Hemsworth is set to have a role in Loki as well.