Throne of Eldraine brought with it a bunch of interesting support cards for the mill archetype, which, when combined with some holdovers from last Standard like Drowned Secrets, give us the critical mass of mill cards necessary to make a (possibly?) competitive deck
Good cards to play with it are auras that cantrip and equipment matter cards
Is Daretti, Scrap Savant better in Imperial Painter than Chandra, Pyromaster
Haste enabler
You then spend all four of your land drops playing and tapping the Simic Growth Chamber and then returning it to your hand, with the end result being that Summer Bloom is a ritual that costs two mana and adds six mana to your mana pool (exactly enough to play a Primeval Titan, which is where things get even sillier, since the lands you tutor up with Primeval Titan untap as well, and you pretty much just win the game on the spot, sometimes on Turn 2)
Unlike Burgeoning, however, you can play your lands from anywhere youre allowed