 However, Gustavus Adolphus' army marched out of camp towards Wallenstein's last known position and attempted to catch him by surprise.This attempted trap was sprung prematurely on the afternoon of 15 November, by a small force left by Wallenstein at the Rippach stream, about 5–6 kilometres south of Lützen.The resulting skirmish delayed the Swedish advance by two or three hours, thus when night fell the two armies were still separated by about 2–3 kilometres (1–2 miles).