The article explores the formulation of the criminal defence of necessity in the context of murder cases. The discussion will provide a medium through which to critique necessity's theoretical foundations which are classified either as one of justification or excuse. It is this highly problematic distinction which will be exposed as not only having been overlooked in case law but is futile where necessity is considered as providing a murder defence. Such a theoretical dichotomy does not reflect the competing rights and values present in the case law, and nor does it align with the decision-making process taken by judges in cases where they resolve such moral conflicts. What is present is a contextual form of necessity that frames and recognises the circumstances the actors are placed in. The analysis argues for a recategorisation of necessity into a narrow fact-driven category beyond the abstract duality of justification or excuse. To support the view of a situation-led approach, necessity is exposed as omitting a critical doctrinal element; that of the imminence of harm within a broader recognition that the situation presents an emergency. Adopting a comparative perspective, the article analyses why the emphasis placed on the imminence of harm found in Canadian jurisprudence ought to be reflected in English law. The rationale for this is to fully reflect the agony of the circumstances that underpin the scope of necessity in murder situations and to ensure that actors in such tragic situations have their rights secured as far as possible, before allowing the defence to apply. One of the final implications of the article is a reconsideration of the relationship between necessity and duress of circumstances arguing that a reappraisal of their convergence is required. The article's argument leaves the juridical precept that duress is not available as a defence to murder on an insecure foundation and in need of judicial re-evaluation.