When Survey Mechan dies, Mortuary triggers, putting Survey Mechan from your graveyard onto the top of your library.
Chalk Outline triggers, creating two creature tokens and two Clue tokens
Resolve the Survey Mechan ability, dealing 3 damage to any target and causing you to draw three cards and gain 3 life.
Activate Ashnod's Altar twice by sacrificing the two creature tokens, adding CCCC.
Cast Survey Mechan by paying 4.
Repeat.
This clever loop relies on Mortuary to intercept Survey Mechan the moment it hits the graveyard, neatly tucking it back onto the top of your library so you can redraw and replay it. As Survey Mechan dies, Chalk Outline triggers upon the creature card leaving your graveyard, generating a steady stream of tokens that Anointed Procession doubles into two Detective tokens and two Clues. You then feed those newly minted tokens right into Ashnod's Altar to generate the colorless mana needed to recast the Mechan and do it all over again.