The idea behind this deck is to gum up the board while accumulating ways to get additional benefits from sacrificing clue tokens.
Creatures
Altered Ego: A great card that can negate an opponent's bomb creature by being a bigger version of it. Can also copy one of your creatures to add more value to clue cracking.
Briarbridge Patrol: A bit meh as a 3/3 for 4, but it can reliably generate clues and cracking 3 in a turn can get you a free creature.
Erdwal Illuminator: A 1/3 for 2 with flying is pretty good. It enhances our ability to create tokens.
Graf Mole: A 2/4 for 3 which makes each cracked clue a source of life. Helps hold the line against most creatures.
Moldgraf Scavenger: A 0/4 for 2 that helps keep the pressure off early.
Tireless Tracker: A 3/2 for 3 with what amounts to 'Landfall - Investigate'. Cracking clues allows it to become a big threat.
Instants
Confront the Unknown: Grants a clue and is a combat trick.
Sorceries
Press for Answers: Allows some breathing room and creates a clue.
Enchantments
Fleeting Memories: Creates a clue when it comes out, and allows cracked clues to mill the opponent for 3.
Ongoing Investigation: Is a source of clues either from its passive or active abilities.
Ulvenwald Mysteries: Creates clues when one of your non-token creatures dies, and cracking clues generates 1/1 tokens. Works well with Tireless Tracker to simultaneously go tall and wide.