The emotions of defence lawyers have garnered little sociological attention. This is surprising, as their role requires them to show loyalty to clients, representing them in court irrespective of the client or the crime. Theirs is thus an emotionally demanding role, requiring the management of inappropriate emotions. This essay explores this by showing that justice systems have structurally embedded emotional regimes guiding emotional performances. My study reveals these invisible rules, along with the ways in which one category of legal professional in particular – defence lawyers – performs its role in the Swedish justice system. The material considered includes fieldnotes gathered from an extensive courtroom ethnography and interviews with defence lawyers. The analysis looks at how defence lawyers perform their duty of loyalty, and finds it to be an interactional accomplishment demanding emotion management and impression management strategies ensuring conformity to the emotional regime of law.