Out of thousands of adjectives in the dictionary I selected those two to fit the case.

What could be more delightful than an abstruse problem in algebra?
You never know along what charming paths of the mind it will lead you.

Moreover there is over it a veil of mystery.

You can't surmise what delightful secrets it will reveal later on.

What will the end be?
What a powerful appeal such a question will always make to a highly intelligent and imaginative mind like mine! No poetry! No beauty! Why every algebraic problem from the very nature of its being is surcharged with it! It's like the mystery of life itself, only in this case we solve the mystery! And if I may change the metaphor, an algebraic formula is like a magnificent diamond, cutting its way through the thick and opaque glass, which represents the unknown! I long for the end of the war for many reasons, but chief among them is the fact that I may return to the romantic and illimitable fields of the mathematical problem!" "I didn't know anyone could ever become dithyrambic about algebra," said Dick.
"What's dithyrambic ?" asked Pennington.
"Spouting, Frank.