Instead, it's right to say that the reason lies in the facts. You asked for the present tense, and it's easy! Quick tip is -broadly, the word lay requires a direct object and lie does not. That said, you can lie down on the floor but you lay your laptop on the table.
Similarly one may ask, what does that's the rub mean?
A The phrase is Shakespeare's. It comes from Hamlet's famous “To be or not to be” soliloquy: To die — to sleep. To sleep — perchance to dream: ay, there's the rub! By rub, Hamlet means a difficulty, obstacle or objection — in this case to his committing suicide.
What does Therein lies the problem mean?
therein lies. phrase. When you say therein lies a situation or problem, you mean that an existing situation has caused that situation or problem. [formal, or old-fashioned]
What is the bard in Shakespeare?
Bard of Avon. A title given to William Shakespeare, who was born and buried in Stratford-upon-Avon, England. A bard is a poet.