| Invitee's obligation, briefly | 33 |
| Invited to one's penthouse, say | 35 |
| Invited a lady to the Flower Ball? | 34 |
| Invite, as to one's penthouse | 33 |
| Invite, as to one's apartment | 33 |
| Invite to the penthouse suite, say | 34 |
| Invite to one's penthouse, say | 34 |
| Invite to one's penthouse, e.g. | 35 |
| Invite to one's penthouse suite | 35 |
| Invite to one's apartment, say | 34 |
| Invite to an impromptu private meeting | 38 |
| Invitation's request, for short | 35 |
| Invitation to wear someone's salad dressing? | 48 |
| Invitation to the stage since 1972 | 34 |
| Invitation to one standing awkwardly near the bar | 49 |
| Invitation to cocktails with pianist Ramsey? | 44 |
| Invitation only given in February | 33 |
| Invitation on a rep's button | 32 |
| Invitation into a writer's home? | 36 |
| Invitation information specification | 36 |
| Invitation for a Gateway Arch date | 34 |
| Invitation acknowledgment (abbr.) | 33 |
| Invitation abbr. concerning drinks | 34 |
| Invisible-clothes wearer in an Andersen tale | 44 |
| Invisible barrier in a sci-fi movie | 35 |
| Invigorating, with "up" | 33 |
| Invigorates, with "up" | 32 |
| Invigorates, with ''up'' | 40 |
| Invigorates (with "up") | 33 |
| Invigorates (with ''up'') | 41 |
| Invests with land, in olden times | 33 |
| Investor's purchase, perhaps | 32 |
| Investor's payment mechanism | 32 |
| Investor's option, for short | 32 |
| Investor's online destination | 33 |
| Investor's concern, familiarly | 34 |
| Investments usually held for yrs. and yrs. | 42 |
| Investments for one's golden years, maybe | 45 |
| Investments for old age, for short | 34 |
| Investment with a 2- to 10-yr. maturity | 39 |
| Investment options for Batman's publisher? | 46 |
| Investment firm's bathroom fixture? | 39 |
| Investment firm with an asterisk in its name | 44 |
| Investment company for a nudist camp? | 37 |
| Investment by a baseball player? | 32 |
| Investment broker's offering | 32 |
| Investment adviser's suggestion, for short | 46 |
| Investment adviser's determination | 38 |
| Investment activity, so to speak | 32 |
| Investing opportunity, for short | 32 |
| Investing largely in money markets, say | 39 |
| Investing formula used by a portfolio manager | 45 |
| Investigators sometimes follow them | 35 |
| Investigator's employer: Abbr. | 34 |
| Investigator of unnatural deaths | 32 |
| Investigator of many accidents, for short | 41 |
| Investigator of family problems, say | 36 |
| Investigator in the USS Cole attack | 35 |
| Investigative reporter's specialty | 38 |
| Investigative reporter's asset | 34 |
| Investigative journalist's report | 37 |
| Investigative journalist's piece | 36 |
| Investigative journalism piece, perhaps | 39 |
| Investigative division (and puzzle theme hint) | 46 |
| Investigation of one person after another? | 42 |
| Investigation into the death of a famous writer? | 48 |
| Investigation into a social networking site? | 44 |
| Investigates, with "into" | 35 |
| Investigated, with "into" | 35 |
| Investigated, with ''into'' | 43 |
| Investigated with "about" | 35 |
| Investigate, with "into" | 34 |
| Investigate (with "into") | 35 |
| Investigate (with ''into'') | 43 |
| Invest with sacerdotal responsibilities | 39 |
| Invest emotion in, to a psychoanalyst | 37 |
| Inversion, such as "Came the dawn" | 44 |
| Inverse function in trigonometry | 32 |
| Inventory ___ (euphemism for shoplifting) | 41 |
| Inventory stock, in adventure games | 35 |
| Inventory in an oenophile's cellar | 38 |
| Inventors may try to build a better one | 39 |
| Inventors : patents :: authors : -- | 35 |
| Inventor–clock-maker Terry | 33 |
| Inventor/electrical engineer Nikola | 35 |
| Inventor's or author's quest | 36 |
| Inventor's "step one" | 35 |
| Inventor's "lightbulb" | 36 |
| Inventor's "light bulb" | 37 |
| Inventor's "impossible dream" | 43 |
| Inventor with an up-and-down career? | 36 |
| Inventor whose last name is a code | 34 |
| Inventor who laid it on the line | 32 |
| Inventor who inspired this puzzle | 33 |
| Inventor who had his ups and downs? | 35 |
| Inventor who had his ups and downs | 34 |
| Inventor who gave skyscrapers a boost | 37 |
| Inventor of wine, according to the Bible | 40 |
| Inventor of the Mothers of Invention | 36 |
| Inventor of the Marching Bands puzzle | 37 |