Given the context, what is the correct way to parse this sentence segment 次に訊くべき言葉が出てこない。?

Question

この寒さをしのげそうな防寒服を手渡され、それを着込みながら僕は彼女に質問した。

「君は……」

[名前なら、ないわ]

こちらから訊くより先に、低く呟くような声が返ってきた。

「呼びにくければアインと呼んで。 いつもそう呼ばれてたから」

質問の出鼻をくじかれ、次に訊くべき言葉が出てこない。

My western brain doesn't know how to understand the bolded segment. It parsed the segment as 'particle-(次に)' 'verb-(訊く)' 'particle-(べき)' 'noun-(言葉)' 'particle-(が)' 'verb-(出てこない)'. I don't know if my parsing is correct or wrong, but I know that the following is true for parsing basic sentences.

Japanese: Subject/topic + object + verb

English: Subject + Verb + Object

Seeing as how there are two verbs in the Japanese segment, how do I understand what the verbs and particles are doing to form a coherent sentence?

Answer 1

Um, you know about Japanese relative clauses, right? If not, I have to say this novel is too difficult for you yet. When you see a verb before a noun, it usually means there is a relative clause involved, although there are a few exceptions.

The main clause of this sentence is:

言葉が出てこない。
Words will not come out. (i.e., I'm at a loss for words.)

This cannot be simpler.

So 次に訊くべき is a relative clause that modifies 言葉. 次に is not a particle but an adverb meaning "next". Note that particles cannot be at the beginning of a sentence. 訊く is "to ask". べき is an auxiliary verb that means "should" (see this).

次に訊くべき言葉が出てこない。
(literally) Words with which I should ask next will not come out.
I was at a loss for next words to ask a question.

_{(I used the past tense because this is an example of historical present.)}

If べき is what threw you off, this べき can be dropped without largely changing the meaning in this case: 次に訊く言葉が出てこない。