Question: Why is the word-order different with 'already' and never' in the following cases:

* *I should never have done it*

and

* *I should have already done it*

Can there be any changes in the word order?
Can 'already' and 'never' break the perfect infinitive? Is it correct to say:

* *They seem to have already done it*

and

* *They seem to have never done it before*

Answer: 
"The" doesn't necessarily refer to something previously identified. Rather, it implies something that is (at least relatively) unique.
Yes, the sentence needs to use **a** in place of **the** to be correct. It is incorrect because there is no prior reference (to establish which beautiful scene), and *the beautiful scene* is a general concept, not a specific or definite thing. [A/an is an indefinite article; the is a definite article](https://owl.purdue.edu/owl/general_writing/grammar/using_articles.html).