Lonnie Machin takes Darhk's wife and daughter hostage and Team Arrow rescues them in episode #410 "Blood Debts".
A group of satanists perform a mock-scarifice and later Lucifer and Chloe arrive to question them about the actual dead girl in episode #112 "#TeamLucifer".
Stein tries to convince Jax to join him but ends up drugging him when that doesn't work in pilot episode "Pilot, Part 1".
Backstrom and Graveley meet with the campus administration about the murder in episode 1x01 "Dragon Slayer".
Cheryl Blossom invites Betty, Veronica, and Archie to her afterparty where she attempts to cause havoc between the three of them in episode #101 "Chapter One: The River's Edge".
In a flashback, Jules waits at home with Maddie so she can introducer her parents to her new wife in episode 1x07 "Frog-Bikini-Eiffel Tower".
Jules and Richard talk their way into a fancy country club in their search for some legal advice in episode 1x07 "Frog-Bikini-Eiffel Tower".