"Mouse" by Fredric Brown

First appeared in Thrilling Wonder Stories.  Reprinted in Everett F. Bleiler and T. E. Dikty's Best Science Fiction Stories and in Ellen Datlow's Sci Fiction.

Bill Wheeler witnesses a cigar-shaped alien ship landing in Central Park.  Inside lies a mouse that has died.  Six days later (enough time to remake the Earth), calamity in various guises strikes different countries.  Bill explains to his cat that whatever inhabited the alien mouse has escaped and is wrecking havoc.  As Bill draws nearer the truth, something unexpected occurs.

Ironic title that mirrors all of the underestimation that goes on by the humans involved--in how the title relates to the cat and how the cat was at one point favorably compared to a wife.  Serendipitously, this mirrors research showing how cats have an effect on their owners.

Commentary elsewhere:

• On Fredric Brown (by Petri Liukkonen -- well done and informative)
• Gary Alan Wassner's appreciation.