When Pharaoh became Egypt's new king, he was not a huge fan of the influence the Jews had.
So he was like "Yo, I'm gonna limit your personal freedom, tax the hell out of you, and force you into slavery, okay?"
As the Jews kept growing in number, Pharaoh was like "OH HELL NO" and ordered all the newborn male children to be thrown in the Nile River.
The mother of a lil bebe was like, "I'm gonna FLOAT him down the river and hope for the best! Bye my lil bebe, it's been real."
This bebe was Moses and he floated down the river and was found by an Egyptian princess who raised him as her own.
Eventually, Moses found out that he was actually Jewish and he was like "WHAAA?!? MOOOOM!"
His adopted mom was like, "yeah but also I kind of saved your life so you can thank me later" and he was like "MY WHOLE LIFE MAKES MORE SENSE NOW."
Moses thought the whole situation was uncool but didn't know what to do. Eventually God was a chill flaming bush and was like "Psst....you should go save your people and lead them to freedom."
Moses wasn't sure but God was like "UMMMM YEAH, I'm God so you should probably listen to me."
When Moses asked Pharaoh for his freedom, Pharaoh was like "Nah, this setup is great 4 me"
Moses was very upset that Pharaoh had zero chill so God promised some zero chill plagues to scare Pharaoh.
So Moses went to Pharaoh and was like "Yo, God just told me there's gonna be a lot of plagues if you don't free us."
After 9 FRICKIN' PLAGUES, the Pharoah was quakin' in his boots but acted like it was NBD.
God was like "FINE, I DIDN'T WANT TO BUT I'LL KILL ALL YOUR FIRST BORNS NOW!"
Pharaoh was still a dummy and literally just yawned in Moses' face and yelled "BOOORING!"*
THEN! God inflicted that promised plague on everyone but the Jews*.
*Jews had to put the blood of a lamb on the doorposts so they could be passed over in the killing. Spoiler Alert! That's why it's called PASSOVER!