THEN WHO WAS PHONE

The fact that the light on the phone never lit up when it supposedly "rang" was the key to the whole thing and an indicator of the larger goings on in the film.

The light never lit up because it was never ringing in the first place. It was in her head the entire time. She had been driven to the brink of insanity by the fact that her son went missing and she never found out what happened to him and that "phone call" was a representative metaphor for him and his mysterious disappearance: it rings but nobody is ever there.

(On a quick side note, I think the disappearance of a child would drive any parent crazy. It's much worse than the child simply dying -- at least with death you get some closure, rather than spending the rest of your life wondering what happened or where your child is and if they are okay)

Combine that enormous baggage with her crappy, claustrophobic residence and the fact that she only has one actual friend in her life, that makes for a bad recipe of someone in desperate mental straights and the ringing phone that's not really ringing is the primary indicator or how unstable she is from the opening frame.

This film is also about how two people who are unstable can easily influence one another and plunge into a "groupthink" mentality and the interesting thing is that not only does Peter influence her with his paranoia, but she influences him, too. Notice that the phone never rings while someone else is there in the motel room? The one exception to this is after she and Peter have sex (which is another metaphor for their characters "joining" each other on not just a physical level, but an emotional, spiritual and pyschological one as well) the phone rings and Peter answers it and he gets the same silence.

This is the story indicating that the two of them have just connected on the same crazy level. We know that the phone was a working phone, because R.C. uses it to make a REAL phone call early on in the story, so if it weren't ringing and the picked it up to answer it anyway, they would at least get a dial tone in their ear. But they don't hear a dial tone -- they only hear silence, which is another indicator that these characters are conjoined on the same crazy wavelength and are only hearing and seeing things that they want to hear. This obviously paves the way for the rest of their decent into madness for the remainder of the story.

The fact that the phone ringing in the credits over the toys and clothes of Lloyd, the missing son, is a dead giveaway that the ringing phone with nobody there is directly related to her son having gone missing and the insanity that it caused for her.

I think an argument could be made for both sides, but personally, i think it was the people who were watching the hotel.

It makes sense, because think about it: they kept calling Agnes (which confirmed SHE was there), but continued calling until Peter picked up the phone. After that, the calls stopped. This is because they had confirmed that Peter had arrived and was definitely in the hotel with Agnes.

I didn't even realize that til just now.

OP wins for thread title alone.

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"It's better not to know so much about what things mean." David Lynch

if you pick up a phone that didn't ring, there'd be a dial tone. There was one part that Michael Shannon answered on her behalf. Unless she somehow conveyed that it was ringing, he wouldnt' have been sharing the same delusion.

I think the phone was ringing because i don't think she was crazy at the beginning of the film. It was her desire to be with a man, which made her start accept paranoid delusions, our of fear of losing him. None of that was happening prior to his arrival.