Sunforger + Officious Interrogation + Mistveil Plains + Time Sieve

Sunforger

Officious Interrogation

Mistveil Plains

Time Sieve

How it works

1. Activate Sunforger by paying and unattaching it, searching your library for Officious Interrogation and casting it without paying its mana cost, plus an additional as necessary.
2. Resolve Officious Interrogation, creating at least five Clue artifact tokens.
3. Activate Time Sieve by tapping it and sacrificing five Clues, causing you to take an extra turn after this one.
4. Activate Mistveil Plains by paying and tapping it, putting Officious Interrogation from your graveyard onto the bottom of your library.
5. Activate Sunforger's equip ability by paying 3, attaching it to any creature you control.
6. Repeat each turn.

This clever loop gives you infinite turns by recycling a single spell right out of your graveyard, turning every rotation of the table into an endless sequence of extra days. You start by using Sunforger to tutor and cast Officious Interrogation for free, netting you plenty of Clue artifact tokens from its investigation effect. Those tokens then fuel Time Sieve, which you sacrifice a batch of five to in order to take an extra turn. Once Officious Interrogation hits the graveyard, Mistveil Plains tucks it neatly back onto the bottom of your library so Sunforger can find it all over again once you reset.