Thing happened from minute 22<br>
At the end of Episode 5, at night, Subaru is sick. He goes out to finding help. He is attacked. At 23:35 to 23:40, we hear the sound of iron weapon (which likely to be Rem morningstar). And Subaru is killed with brute force.<br>

[![image1][1]][1]

However, it is unclear why Rem do that. Because the relationship of Rem and Subaru is looking good. They both going to the village and have some talk. Rem also look happy then (at 17:29).  <br>

[![image2][2]][2]<br>
 
I did watch Episode 6, Subaru is very distance from Rem, and he is suspicious, along with witch scent that gets him killed. But does Rem kill Subaru in Episode 5 for same reason ?<br>
<br>
**Edited**: From @ObviouslyJake answer, I would like to add some more detail
Comparing from the time frame in Episode 5 and Episode 6 <br>
Similar: Subaru's **witch smell** (which is the main reason, according to @ObviouslyJake)
Different: the relationship with Rem 
    Episode 5: They talk, go downtown together. Rem is happy. (at I said above, with picture). In this episode, I can feel that Rem and Subaru become friends.
    Episode 6: Rem tries to be distance from Subaru. Also, Subaru fall in her garden twice, which she has to fix it. In this Episode, Rem and Subaru are strangers.  <br>
Is the difference in the relationship between Subaru & Rem contribute to Subaru death at the end of Episode 5, comparing to Episode 6. Or the **Witch Smell** is the only reason ? <br>

Because there is two Episode, with some **different choose**, **difference path**, I think it must be something **different** here. I feel it have to be, but I can't find it. <br>

Sorry for my bad English and writing skill. (mod please improve it if possible) <br>

Thank you <br> 

  [1]: https://i.sstatic.net/DraOV.jpg
  [2]: https://i.sstatic.net/hvPt3.jpg