A conflict of interest is not a personal failing of one lawyer. It is a firm-wide disability that attaches to every lawyer in the office the moment one of them is disqualified, and it can arrive without anyone doing anything wrong at all. Imputation is the doctrine that does most of the work in this field, and screening is the mechanism that sometimes undoes it. This article explains how current-client and former-client conflicts differ, why the substantial relationship test asks about information rather than loyalty, when a client can consent and when consent is unavailable, how a lateral hire can disable an entire firm overnight, and why the remedy sought in litigation — disqualification — is governed by an entirely different calculus from the ethics rule that defines the violation.