What do you do with a muy bad day? In this heartwarming dual-lingual picture book from debut author Melanie Wick Singer, with illustrations by Natalia Jimenez Osorio, one girl learns from her grandmother how to turn a muy bad day into a fiesta! Martina just had the worst day, ever. She fell in a mud puddle, swallowed a bug, stepped on un grande wad of gum, and ruined her lucky calcetines forever! When she tells her grandmother all about her muy bad day, Abuela has a few ideas for how to handle all the big feelings. Will anything be enough to turn Martina's muy bad day around? With lively and vibrant illustrations from Natalia Jimenez Osorio and English text with Spanish words woven in from debut author Melanie Wick Singer, this heartwarming grandmother-granddaughter picture book reminds us that with humor, love, and a little bit of music, anyone can turn un dia muy malo into a fiesta, because even the worst days are worth celebrating.