The Fugitive Doctor

If you cast an instant or sorcery with {X} in its mana cost this way, you must choose 0 as the value of X. (You still have to pay {2}{R}{G}.)

If a split card gains flashback, you pay only the cost of the half you're casting.

Unlike other creature types in Magic that are each only one word, the two words "Time Lord" represent a single creature subtype. Time Lord is the only two-word creature type.

"Investigate" means "Create a Clue token." A Clue token is a colorless Clue artifact token with "{2}, Sacrifice this artifact: Draw a card."

To determine the total cost of a spell, start with the mana cost or alternative cost (such as a flashback cost) you're paying, add any cost increases, then apply any cost reductions. The mana value of the spell is determined only by its mana cost, no matter what the total cost to cast the spell was.

A spell cast using flashback will always be exiled afterward, whether it resolves, is countered, or leaves the stack in some other way.

"Flashback [cost]" means "You may cast this card from your graveyard by paying [cost] rather than paying its mana cost" and "If the flashback cost was paid, exile this card instead of putting it anywhere else any time it would leave the stack."