Neutrons are a unique probe to find out ‘where atoms are and what atoms do’ in materials. They provide complementary information to X-rays, they are highly penetrating but non-destructive and have the advantage that they see hydrogen and deuterium differently, thus enabling isotopic labelling. The UK hosts a world-leading neutron facility, the ISIS Neutron and Muon Source, which is available for scientific research in a broad range of fields. In this seminar, I will run through what ISIS is and how it works, and give you a flavour of the type of information that one can get from the different neutron techniques. I will cover a wide scientific remit, but will spend more time talking about my expertise in bio-related and soft matter examples.