Just a quick FYI, because @Dr_B mentioned turning the light on and off. For the sake of the scene we are gonna say he's been doing something period-appropriate with a candle (covering or shading it in some way), but keep in mind that electricity, gas and even lighters and matches are still quite far in the future. If your characters find themselves in a dark place without a light or the one they carry gets snuffed out, there is no easy and convenient way to light it again.