To nobody's great surprise Mercedes drivers topped the first official practice sessions of the 2015 Formula 1 season, but Friday in Australia threw up several fascinating storylines.
The revival of Ferrari, McLaren-Honda's stuttering start and the phoenix-from-the-ashes return of Manor-Marussia meant there was plenty to look out for across the three hours of practice at Albert Park in Melbourne.
So what did we learn? And what can we expect in qualifying and in the race on Sunday? Ben Anderson, Lawrence Barretto and Edd Straw are your guides.