"And they'll also hold an all-night festival that will be worth seeing."
[Pol. here uses some of the same language S. had used in the first sentence of the dialogue to describe why he went down to the Peiraeus. S. went down theasasthai, to see. (Literally, the last phrase is "that worthy to see.") Both Pol. and S. want to see, that is, to be spectators: S. of "the manner in which they would perform the festival" and Pol. of the "all-night festival." S. says the procession was kalos, fine or noble; Pol. says the all-night festival will be axios theasasthai, worth seeing.]