If the letters of the word 'RUTHENIUM' are arranged in English alphabetical order, which letter will be second to the right of the middle letter?

1. The original word is 'RUTHENIUM', consisting of $9$ letters.
2. Arranging the letters in alphabetical order gives:

$$\text{E, H, I, M, N, R, T, U, U}$$

3. The middle ($5\text{th}$) letter is $\text{N}$.
4. The letter second to the right of the middle letter is the $7\text{th}$ letter ($5+2=7$).
5. The $7\text{th}$ letter in this sequence is $\text{T}$.