4.5 stars! 
 I read this one aloud to me 13-year old son, as I did the first one. We both enjoy the humor Stroud interjects in these stories, which are also kinda creepy, and heavy on mystery, though my son grants it a straight-up 4 stars. 
 Although I love the characters that form the Lockwood & Co. ghost wrangling company, my son's favorite character, and one that brought on much of the comic relief, is the Whispering Skull itself. To punctuate what we figured the skull must be feeling after some of its lines, my son would add in "LOLZ", which made things even funnier. 
 Anyway, Stroud has refined his writing and found the sweet spot of descriptions that fill your head with visions without going on and on about whatever is being described. Also, there's his sense of humor, as I mentioned. While I hesitate to put this title on my 'humor' shelf, I did laugh out loud many times. Here's one bit I particularly enjoyed: 
 "It was our old friend, Ned Shaw. Gray, disheveled, and whey-faced with weariness, he stood like an ugly mailbox on the opposite side of the road, stolidly watching our front door." 
 There's also: 
 "But today his face shone, his eyes sparkled. If he'd been lucky enough to possess a chin, it would no doubt have been jutting with excitement." 
 And plenty more. It's such a fun series, bring on the next one!