Translation:The emissaries are talking to each other.
in the German edition of the TKD (2nd. edition) I found "ja'chuq" as a verb with its first meaning "discuss" what often (though not necessarily) is the same as to talk to each other. Couldn't "discuss" be accepted as a right answer? Is there a difference in the German and the English version of the TKD in handling "ja'" and "ja'chuq". More general: should I rely more on the English TKD (which I so far did not purchase, as the 2nd. edition of the German TKD worked fine for me)?
In English, discuss is a transitive verb, meaning there should be an object that is being discussed. Since there is no object in this sentence, discuss is not an appropriate verb to use. You can't say The emissaries are discussing. You have to say The emissaries are discussing SOMETHING.
The Klingon Dictionary also translates ja'chuq as confer, which you could use here. The emissaries are conferring.
ja'chuq literally means tell each other. In English, this is also a transitive phrase: you have to say WHAT you are telling each other. In Klingon.
I consider talking to each other to be a barely adequate translation. ja'chuq does not necessarily imply talking. You can ja' someone something through email or telepathy or smoke signals and it's not talking. (The English sentence in this sentence should really change talking to to conferring with to make this a better translation.)
The Klingon definitions were invented by an English speaker with an English-speaking audience in mind, so using the English TKD as your primary source is preferred. Once upon a time the German TKD had lots of errors; I don't know if that's still the case.
Thanks for the answer. I can see now yet another difference between German and English. In German "diskutieren" can also mean just to have a discussion without knowing the item. As the request for a German Klingon course will be much too low in the foreseeable future, I have to stumble on with English :(. jdmcowan already mentioned Quvar: For Germans it is highly recommendable to avoid the 1. edition and stick to the second ed. of the TKD.