My Laptop is also involved now . It tells me the hard drive is missing. WTH....
Do you have a clean backup of your machine. One that you are sure hasn't been messed with?
I recommend option + command + r
command + r
to boot from your recovery partition.
if command + r does work then either your partition tables have become corrupt, your recovery partition has become corrupt, or you drive has problems.
option + command + r
This load a the latest copy of macOS off of Apple's servers.
power off the machine. wait one minute or so. hold the option key down. power on. hold down until you see some thing on the screen. Do you see anything?
other keys
Startup key combinations for Mac - Apple Support
https://support.apple.com/en-us/HT201255
more about recovery
About macOS Recovery - Apple Support
https://support.apple.com/en-us/HT201314