TPM Genie is a serial bus interposer that is designed to aid vulnerability research on Trusted Platform Modules. Levering TPM Genie, I demonstrate how to undermine most of the stated purposes of the Trusted Platform Module - measured boot, remote attestation, sealed storage, and the hardware RNG. Additionally, I show how a TPM interposer can trigger other errors in the fragile host-side response parsing code. Combined, these issues allow an attacker to compromise measured/attested boot on a large number of TPM-enabled machines.