Blood and Ichor — Sarah A. Hoyt

Living in the country, they'd come to expect the occasional abandoned animal. But they never expected anyone to be so callous as to toss a bundle out the window of a speeding car. Nor did they expect it to hit their own vehicle. But it's what they find when they unwrap the white bundle and find something straight out of a child's fairy tale that changes their lives forever.

This short story is also available as part of the collection Blood Ransom.