That is actually the title of a classic detective novel by Raymond Chandler, but the long and short of it is that there are a number of ways to say goodbye in German – some of them longer than others! Let's start with what you probably already know:
Ja, damit sind wir fertig. Auf Wiedersehen!
Yes, with that we are finished. Goodbye!Play Caption
Ich sehe Sie dann morgen. Auf Wiederhören.
I'll see you tomorrow then. Goodbye.
Caption 52, Berufsleben: das VorstellungsgesprächPlay Caption
Because of the -sehen in Wiedersehen ("see you again") and -hören in Wiederhören ("hear from you again"), auf Wiederhören is the proper form to use on the telephone.
Wiedersehen, vielen Dank! -Tschüss. -Tschüss.
Goodbye, many thanks! -Bye. -Bye.
Caption 25, Großstadtrevier: Von Monstern und MördernPlay Caption
Tschüss is an informal waym of saying goodbye that originally stems from the Spanish word for goodbye, adios.
Bis morgen. Ciao.
See you tomorrow. Ciao.Play Caption
"Ciao" is actually from the Italian and can, depending upon the context, be used for hello or goodbye. It is not even translated as "bye" here as it has been adopted into English by most American and British dictionaries. It's usage in German is very informal.
Sie wissen schon, was wir meinen. Adieu.
You do know what we mean. Adieu.
Captions 64-65, Die Pfefferkörner: EndspurtPlay Caption
The French word for goodbye, adieu, has also been adopted by English and is thus generally not translated.
Ich hab was vergessen. -Aha. -Wir sehen uns.
I forgot something. -Aha. -See you.
Caption 66, Die Pfefferkörner: EigentorPlay Caption
It is also common to say Wir sehen uns morgen ("We'll see each other tomorrow" or "See you tomorrow"), or Wir sehen uns wieder ("We'll see each other again"), and so forth. It sounds a bit impersonal to the ears of an English speaker, but you can also say man sieht sich, which translates as "We'll see each other" or simply "See you."
Mir hat's super gefallen. Bis dann!
I really enjoyed it. Until then!
Caption 93, Frisbee: Karlsruher WeihnachtsturnierPlay Caption
Hast du die Mathehausaufgaben denn schon fertig? -Ja, bis später.
Have you finished the math homework already? -Yes, see you later.
Caption 2, Knallerfrauen: MathehausaufgabenPlay Caption
Mach's gut, Herbert. Bis bald.
Take care, Herbert. See you soon.
Caption 4, Nicos Weg: Tschüss!Play Caption
Bis zum nächsten Mal.
Until next time.
Caption 21, Berlin: Domäne DahlemPlay Caption
Many of the ways to say goodbye using bis and some point in the future may be translated, depending upon the context, as either "till," "until," or "see you..." So if somebody says bis morgen, you could translate it as "till tomorrow," "until tomorrow," or "see you tomorrow."
Note that macht's gut, which could be literally translated as "fare well" or "farewell," is used as an informal way to say goodbye in some German regional dialects. Another good equivalent translation could be "have a good one."
But how do you say "to say goodbye" as in "to take leave" of somebody? The most common ways are Abschied nehmen and the reflexive verb sich verabschieden:
Aber als Flüchtling muss man eben oft Abschied nehmen.
But as a refugee, you often have to say goodbye.
Caption 35, Filmtrailer: Als Hitler das rosa Kaninchen stahlPlay Caption
Und hier verabschieden wir uns auch von euch.
And we will say goodbye to you here.
Caption 39, 48 h in Innsbruck: Sehenswürdigkeiten & TippsPlay Caption
I hope that learning about goodbye didn't take too long—this is a lesson and not a novel, after all! Look for some of the ways of saying goodbye on Yabla German, and take special note of how some are used in formal contexts and others in more casual situations. So until next time, mach's gut and stay healthy!