My research is on the high energy emission from accreting binary stars and gamma-ray bursts. Accreting white dwarfs show a huge variety of observational properties giving clues to the physics of their accretions disks their magnetic fields and on their interaction. More recently I have focussed on classical novae in which the white dwarf undergoes runaway thermonuclear burning after having accreted sufficient material to reach ignition pressure. X-rays from the ejecta shocks and the burning white dwarf can be used to diagnose the underlying binary system potentially leading to an understanding of the progenitors of the type Ia supernovae used to measure the acceleration of the Universe. The Swift satellite was the first built specifically to study gamma-ray bursts. It has revolutionised the field by locating thousands of bursts so that their redshift (distance) can be measured. Bursts from when the Universe was just 3-4% of its current age have been found constraining its evolution from the Big Bang. A spectacular highlight was the discovery in 2017 of the first ever electromagnetic counterpart to a gravitational wave promising a great future for this field.