Collisions of lead nuclei in the LHC form the hot, dense medium known as the quark-gluon plasma (QGP). Experimentally, the QGP is characterised by the collective flow of emerging quarks and gluons. They fragment into highly collimated “jets” of particles that in turn lose energy through a phenomenon known as jet quenching. Studying this effect can improve the understanding of quantum chromodynamics, the theory of the strong nuclear interaction that governs the behaviour of the QGP.