Aeroplanes in clouds, submarines in murky water and cancerous tumours in breast tissue all have one thing in common – they are objects hidden in highly scattering media. Imaging through such media remains one of the most challenging problems in science and engineering but the advent of ultrafast lasers and detectors, coupled with a range of time-resolved techniques, has led to breakthroughs. Interest is currently focused on developing a time-resolved imaging technique to detect breast cancer tumours as early as possible.