Araucaria was as enjoyable as ever, complete
with the usual statutory twist! He had me literally "in a corner" with 23ac, where the
clue is "Absolutely sound". Straightaway I put in "UTTER" and for 23down, which incorporates the drug "E", I half-heartedly imagined it to be "USERS", but thankfully never wrote this in. As fellow-Araucarians will know, "utter" is hopelessly wrong, along with the much-less-likely "users"! I just wanted to mention, as other solvers will doubtless know, how easy it is to sometimes go astray on these more mind-searching compilations!