No-one predicted that scenario four months ago when Thierry Henry - Gunners captain, talisman and record scorer - left north London to join Barcelona.
In fact, BBC Sport's Alan Hansen said: "Arsenal are the one team out of the so-called top four that could be vulnerable. And I am not so sure they have a chance of winning the Champions League."
What is behind their resurgence - and can they sustain it?
What are these?