I was reading the Avengers story arc where Count Nefaria becomes temporarily immortal (#164-166) and right at the end of #165 Thor suddenly appears for an unknown reason. Is this occurrence explained in a future issue or in Thor's own book? Was it due to the ability of the Scarlet Witch? A few pages before Thor's arrival we see her thinking "Thor! If only he'd stage one of his mysterious, last minute arrivals now, as he has so often of late!". Did she somehow use her powers to summon him? That's pretty impressive, especially back then.