When Voldemort returns in Goblet of Fire, Dumbledore attempts to reorganize the Order of the Phoenix as soon as possible. In pursuit thereof he gives the following instructions to Sirius:
Sirius, I need you to set off at once. You are to alert Remus Lupin, Arabella Figg, Mundungus Fletcher — the old crowd. Lie low at Lupin's for a while; I will contact you there.”
How exactly could Sirius accomplish this? Sirius was at the time the most wanted wizard criminal in the country (if not the world). The only ones who believed he was innocent were Dumbledore, Harry, Ron, Hermione, and Lupin. How exactly could Sirius just show up to old Order members and tell them that Voldemort had returned and the Order was being restarted? In fact, in the beginning of Order of the Phoenix this very line of reasoning is given to explain why Sirius couldn't do anything for the Order:
“Well, as everyone thinks I’m a mad mass murderer and the Ministry’s put a ten-thousand-Galleon price on my head, I can hardly stroll up the street and start handing out leaflets, can I?” said Sirius restlessly.
What exactly was Dumbledore expecting Sirius to do at the end of Goblet of Fire?