"Nay, thou need not descend the steps, Percy. Nars and I shall deal with the broken sword, though it may be too unclean for thine hands to touch.
Fortune be with us for my delvings in the arcane arts provideth me a way to unerringly decipher magick writings and clean small items, such as the broken sword. These be simple cantrips, that perhaps thou canst perform on thy own, if thou wishest. Canst thou study these writings while the Master Blackbeard and I go below?"
Ishmael will attempt to tip the cauldron (with Nars' help), clean the sword pieces (with Prestidigitation) and finally, go back up. If Percy can't decipher the magick writings by then, he tries casting Read magic (if it would help).
After trying to glean any insights from the papers does Ishmael finally enter the small tunnel. He reassures the rest of the party that he will be careful before exploring.