Little Blue Truck feels, well, blue when he delivers valentine after valentine but receives nary a one.His bed overflowing with cards, Blue sets out to deliver a yellow card with purple polka dots and a shiny purple heart to Hen, one with a shiny fuchsia heart to Pig, a big, shiny, red heart-shaped card to Horse, and so on. With each delivery there is an exchange of Beeps from Blue and the appropriate animal sounds from his friends, Blue's Beeps always set in blue and the animal's vocalization in a color that matches the card it receives. But as Blue heads home, his deliveries complete, his headlight eyes are sad and his front bumper droops ever so slightly. Blue is therefore surprised (but readers may not be) when he pulls into his garage to be greeted by all his friends with a shiny blue valentine just for him. In this, Blue's seventh outing, it's not just the sturdy protagonist that seems to be wilting. Schertle's verse, usually reliable, stumbles more than once; stanzas such as "But Valentine's Day / didn't seem much fun / when he didn't get cards / from anyone" will cause hitches during read-alouds. The illustrations, done by Joseph in the style of original series collaborator Jill McElmurry, are pleasant enough, but his compositions often feel stiff and forced.Little Blue Truck keeps on truckin'-but not without some backfires. (Board book. 1-4)